Mesh won't texture?

[mystrawberrymilk]

Ahhhh hello forum!! ♡

I'm so sorry if I'm about to ask an obvious noob question but I'm a bit stumped. Maybe I'm missing obvious things without knowing ^^. I'd appreciate anyone willing to lend a hand ~!!

So my problem is, recently I've begun making mesh. I go to apply a texture to it and it doesn't like... Take? It will apply but very strangely or simply not at all. If it does its Stretched and blurred. I thought okay, it's my noob texturing skill. I messed up. So I put the project aside for a bit.
But then I had bought a shirt off of the MP and it had a texture mod. I went to apply it and again, it would not apply to the mesh even after clicking it to or dragging it--(yes the shirt had modify permissions and it went into unlocked edit mode when trying) and if it did apply, the texture was stretched and blurred like before. So this made me realize that the problem probably isn't with how I made my own texture? Maybe I'm applying it wrong ? It doesn't seem so.

I am hoping maybe someone can offer a suggestion or two? Thank you very much for even reading at all ^^

[Madeliefste Oh]

Modeling a mesh is one part of the art, the other one is making an UV map.The UV map is a template for your texture. You must make one before you can texture your mesh.

An example of how a UV map can look:

A model with the UV map:

The texture:

The model with the texture: