UV unwrapping in blender

To texture a model you must unwrap it for the texture to fit onto the model nicely. An unwrap is a 2D representation of a 3D model. To start creating a UV unwrap you will need to go to the top bar and select the tab "UV Editing". You could just select the whole mesh and unwrap that however, sometimes it won't work for some meshes so you will need to create 'seams'. To create a seam you will have to select an edge and right click, then go down and find 'Mark Seam' and then the line you marked will turn red. You can mark multiple seams by selcting multiple lines and using the same process as usually by holding shift and clicking. Marking a seam seperates the polygons from eachother which makes it easier to categories your map and not have them be all one big 2D shape.