I’m trying to apply a texture to a cylinder but, I have no idea how to apply to it as a whole, it keeps assigning the texture to only one of it’s faces at a time
You either drag & drop it. Or choose it from a drop down of that mesh. Or select the material in the content browser and hit a white arrow next to the mesh:
How are you doing it?
Dragging and dropping selects only one face, and selecting the whole model doesn’t give me the option to apply a material
Ah, you’re editing a brush.
Either select the material in the content browser first and then drop the brush into the level - it will have this material applied automagically.
Or convert the brush to a static mesh and then apply material: