Ok, so I am not good at multi-classing, but I am practicing. I have made a lvl 11 character, that is lvl 6 ranger, lvl 3 warlock and a lvl 2 tempest cleric. Is there any way I can make this actually work and actually be good, because I have got told that this won't work and I want to try and prove them wrong. 

It largely depends on what you want to achieve. What is the idea behind this build? What are the Ranger and Warlock subclasses?

The current info make it difficult to help you I am afraid :(

Quote from LeK >>

It largely depends on what you want to achieve. What is the idea behind this build? What are the Ranger and Warlock subclasses?

The current info make it difficult to help you I am afraid :(

 My Ranger is a Hunter Conclave, and my Warlock is a Celestial Subclass.

Ok, that helps already.

What is your character idea? How do you envision them? What would you want to achieve with their abilities? (in general terms, not strictly D&D terms)

Quote from LeK >>

Ok, that helps already.

What is your character idea? How do you envision them? What would you want to achieve with their abilities? (in general terms, not strictly D&D terms)

 Well I kind of want him to be decent in ranged fighting, that deals quite a bit of damage, (I already took the archery fighting style with ranger).

I envision him to be pretty powerful.

My achievements with this character is to see how well I can play as him. Kind of to prove that this kind of character can be good as well. 

I'll add my pdf link so you can take a look as well.

https://documentcloud.adobe.com/link/track?uri=urn:aaid:scds:US:459911ac-1c50-464b-b143-74670f2beaf0

Making a character out of spite isn't necessarily the best way to go about having a good D&D experience.

If your only goal / background for the character is "I want to be good at ranged combat and deal a lot of damage" then putting max levels into warlock OR ranger would be better. Your ranged attacks for warlock are based on CHA (eldritch blast) and ranger is dex (bow). Your tempest feature doesn't synergize much with anything those classes offer except for a ranger's lightning arrow spell, but you cant take it as you need to be ranger 9 for 3rd level spells and your multiclassing has delayed your spell progression.

Mechanically the best feature I see out of this particular multiclass combination is it makes a great healer. You get all the cleric goodness, bonus action heals from warlock, and healing spirit from ranger.

Here's how I'd do that:

Point buy for stats.  Str 8 (0), Dex 15 (9), Con 12 (4), Int 10 (2), Wis 15 (9), Cha 11 (3).  Half-elf, boosting Dex and Wis.  Use your ASI on Dex.  Maybe move one point from Int to Cha. 

You have two 2nd-level spell slots from warlock and four 1st-level slots, three 2nd-level slots, and two 3rd-level slots from cleric and ranger.  You know four warlock spells of 2nd level or lower and four ranger spells of 2nd level or lower and can prepare five 1st-level cleric spells.  You also know three cleric cantrips and two warlock cantrips, plus your Celestial cantrips.  You also know two Eldritch Invocations. 

Consider Improved Pact Weapon if you choose Pact of the Blade.  Other good invocations include Beast Speech, Devil's Sight, Eyes of the Rune Keeper, and Mask of Many Faces.  Probably Pact of the Blade or Chain. 

Warlock cantrips: Minor illusion and mage hand or prestidigitation. 

Cleric cantrips: Normally I'd suggest guidance, but you have too many other things competing for your out-of-combat concentration, so mending, thaumaturgy, and toll the dead as a backup ranged option (maybe take guidance instead anyway).  

Get hex or hunter's mark.  You can use your warlock slots to cast pass without trace and your 3rd-level slots to cast armor of Agathys.  Absorb elements is good for staying alive, as is mirror image.  Other good warlock spells are hellish rebuke and lesser restoration (from Celestial), but not misty step--you don't need to worry about melee. 

Clerics get ritual casting, but rangers don't and warlocks need to work for it.  Your cleric spells should therefore include detect magic, detect poison and disease, and purify food and drink. 

Colossus Slayer as your 3rd-level Hunter option, of course. 

I'm kind of falling in love with this build, actually.  In combat, it's a striker and a tank; out of combat, it's still incredibly useful.  And it heals.