Hi all,

If you started as a Tabaxi | Gloom Stalker Ranger with the intent of only multi-classing into Rogue, how would you go about developing resistance/immunity to slashing, radiant, and piercing damage as quick as possible?

I would prefer that i didnt incur disadvantage on stealth, but it's not a deal breaker.

I guess really we are talking about picking up items?
After all, such a character isn't very magical.

Pretty sure absorb elements does not help with radiant.

Thanks in advance

That's a lot of resistances and the quickest way is probably multi-classing into Bear Totem Barbarian. Other than that, you're probably looking at rings or armor of resistance for radiant. A quick item search didn't turn up anything for slashing or piercing. There was some cursed armor that would work, but you'd be vulnerable to something else. Items are also controlled by the DM so they'd have to be good with all that too. There are spells like stoneskin that someone else could cast on you or maybe you could use a potion (or learn how to make them). Again, that's really up to the DM. 

Yeah, Ring of Radiant damage or armour infused with radiant resistance... ticks one of the boxes.

I guess just raising my AC as high as I can with cloak, rings, bracers is probably the best way to tackle the piercing/slashing.
Not really a resistance to the types of damage, but rather just making it harder for an enemy to hit me.

I'll need to figure out the most coin/time efficient way of increasing my armour without getting disadvantage on stealth rolls

This character is in one of those discord MMO style D&D formats.
So different DM's for each mission.

Time to suck up to an artificer lol

There aren't many ways to get resistance to physical damage.  Basically you're limited to barbarian rage if you want magical damage to be included, or the capstone ability of a few classes to get resistance to nonmagical only.  Starting from the OP's position I wouldn't be trying to get any of those resistances.