Hard to play easy to dismiss in 2024 rules

If possible, I'd not replace a wizard or a cleric with a bard, since these classes may call upon divine powers or access the biggest spell list with the best spell rotation (wizards may replace one of their cantrips every long rest and, starting at 5th class level, one of their prepared spells with another from their book every short rest. No other class competes with a wizard's spell rotation, and they may also cast their rituals without preparing them).

Context for spell selection: Picture the rogue or the ranger, these guys seem good with tools/weapons, they've got expertise, get things done, bards have some of that, proficient with musical instrument, full spellcasting slots, too bad the slots only refill after a long rest, that's how leomund's tiny hut may come in clutch, some wild animals may sniff and ignore it, etc. They also say ranger may take frontline like other beefy classes, but bard's more like the rogue, bad armor, less than a d10 in health, don't get in trouble alone or it will hurt and more.

1st Level: 0+2=Two 1st Level Spell Slots, 0+2=2 Cantrips, 0+4=4 Preparations. How about a ritual, like unseen servant? Works like a mage hand cantrip, we delay mage hand and have a leveled ritual queued for a later swap. With only two slots for the day, other spells could be usable in a fight, maybe healing word, faerie fire and heroism at this level, there was a time a big enemy caused the frightened condition at 1st character level, fight would've gone smoother with heroism that's how I feel, plus it's thematic the bard singing someone else an inspiring song or something. There are other good options, if you got a mount, if the terrain will be a problem, if you're the only spellcaster, if everyone else is much stronger, there are many variables affecting your decision, I'm just opening with a string of options that could be good. Oh, by the way, do pick the starry wisp cantrip because zombie's undead fortitude is a thing. Maybe you're playing an undead bard and the zombies are your allies? No way for me to know what's what. Would also go for vicious mockery since it's a saving throw it won't get disadvantage like starry wisp when using it as part of the war caster feat which I'm eyeing for now and it can also be cast hands free!

2nd Level: 2+1=Three 1st Level Spell Slots, 4+1=5 Preparations. Could add detect magic to spot stuff like a magic trap or something. Expertise perception and sleigh of hand.

3rd Level: 3+1=Four 1st Level, 0+2=Two 2nd Level Spell Slots, 5+1=6 Preparations. New way to deal with fright may be the calm emotions spell (it says on saving throws that a creature may choose to fail a saving throw without rolling), there was an annoying enemy that made themselves invisible at this level one time, consider replacing heroism with see invisibility. There may be better options depending on what you need and you know what you need better than I do. Look for someone to maintain a warding bond spell on ya, yeah? :) It splits the damage, you wanna split the damage an ally would take across multiple allies to reduce damage taken per ally while focusing on defeating one enemy at a time! Defeated foes stop fighting so your group takes less damage.

4th Level: 2+1=Three 2nd Level Spell Slots, 2+1=3 Cantrips, 6+1=7 Preparations. War caster feat would make concentration spells last longer, may choose cloud of daggers, get mage hand, swap unseen servant with cure wounds because next is 5th level and maybe you get to team up with someone able to maintain a beacon of hope spell which I'm also adding to this character but only at 16th level unless there's good reason to put it before other spells like there's a bunch of fullcaster allies with cure wounds prepared or something, your party composition pitted against enemies you already encountered and expect to keep facing means your guys benefit way too much from advantage to wisdom and death saves, idk.

5th Level: 0+2=Two 3rd Level Spell Slots, 7+2=9 Preparations. Leomund's tiny hut, dispel magic and replace detect magic with hypnotic pattern or something, hypno's gonna be better depending on who you're playing with, raging berserker barbarian doesn't get charmed at 6th level and devotion paladin also doesn't get charmed, but it's at 7th level.

6th Level. 2+1=Three 3rd Level Spell Slots, 9+1=10 Preparations. Detect magic. College of lore subclass consider counterspell.

7th Level. 0+1=One 4th Level Spell Slot, 10+1=11 Preparations. Could replace faerie fire with polymorph and dimension door.

8th Level: 1+1=Two 4th Level Spell Slots, 11+1=12 Preparations. Perhaps resilient constitution feat to make concentration more reliable, the aid spell and, if playing college of lore, would also get the fire shield spell through the subclass' 6th level feature called magical discoveries, from now on I'm assuming this bard is of the college of lore subclass.

9th Level: 2+1=Three 4th Level, 0+1=One 5th Level Spell Slots, 12+2=14 Preparations. May get yolande's regal presence and freedom of movement. Expertise acrobatics and investigation.

10th Level: 1+1=Two 5th Level Spell Slots, 3+1=4 Cantrips, 14+1=15 Preparations. Maybe the light cantrip and now that we get to pick leveled spells from bard, cleric, druid and wizard, replace hypnotic pattern with circle of power and rope trick.

11th Level: 0+1=One 6th Level Spell Slot, 15+1=16 Preparations. Replace freedom of movement with heal and tasha's bubbling cauldron, get oil of slipperiness from the spell to fulfill the role of the freedom of movement spell for up to 8 hours per item or get different allies carrying potions of greater healing or something. Lore swap fire shield with find familiar bat for their blindsight, may upcast 5th level aid on the bat familiar.

12th Level: Inspiring leader feat, replace calm emotions with counterspell. Lore replace counterspell with sanctuary, could be useful on the bat familiar like the inspiring leader feat.

13th Level: 0+1=One 7th Level Spell Slot. 16+1=17 Preparations. Replace see invisibility with conjure celestial and get death ward that could be useful on the bat familiar, conjure celestial relies on sight and enemies may have stuff to obscure truesight like the fog cloud spell or another trait, but blindsight from a bat should work! If you also went with the alert origin feat, the bat is another ally on initiative to target with the feat :)

14th Level: Replace polymorph with fly to keep up with subclasses (aberrant, draconic sorcerer, etc) that grant fly speed at this or earlier levels.

15th Level: 0+1=One 8th Level Spell Slot, 17+1=18 Preparations. Replace yolande's regal presence with mind blank and spirit guardians that doesn't rely on sight. Bard's low armor class dodge is more to reduce the chance of getting critically hit than to avoid the hit altogether.

16th Level: Ritual caster feat find familiar bat for blindsight, detect magic, unseen servant, identify, comprehend languages. Replace mage hand with mending, lore find familiar with mordenkainen's magnificent mansion and detect magic with beacon of hope!

17th Level: 0+1=One 9th Level Spell Slot, 18+1=19 Preparations. Replace cloud of daggers with prismatic wall, wish, detect poison and disease from ritual caster feat. If there are days off, wish could duplicate stuff that's still active after a long rest such as find steed, contingency, heroes' feast, etc.

18th Level: 2+1=Three 5th Level Spell Slots, 19+1=20 Preparations. Mordenkainen's magnificent mansion. Lore replace it with chill touch to foil enemy healing combo with peerless skill 14th subclass level feature. Again, there may be more suitable options and only you should be making final decisions for your character with DM's consent.

19th Level: 1+1=Two 6th Level Spell Slots, 20+1=21 Preparations. Revivify and desperate resilience epic boon from forgotten realms: heroes of faerûn if possible.

20th Level: 1+1=Two 7th Level Spell Slots, 21+1=22 Preparations. Gentle repose since getting brought back to life after death by 7th spell level resurrection with all hit points or 5th spell level raise dead with 1 hit point, both accessible through the wish spell, does -4 to d20 tests, which would take 4 long rests to remove, leaving creature up until then with a debuff that could be avoided by initially combining gentle repose (if casting it as a ritual, ritual caster feat could help) and revivify without resorting to wish or casting it after resting once, plus revivify spell scrolls may be more accessible end game.

Best of luck! This topic is part of another, 2024 Battle Performance: https://www.dndbeyond.com/forums/dungeons-dragons-discussion/tips-tactics/231317