Quite a lot of getting better at chess is just noticing what is going on -- which pieces can be taken? Can the capturing piece be taken after that?

There's a nifty game called Solitaire Chess by Thinkfun which is fun in itself and also helps you practise just this and other chess skills -- like trying things out in a different order.

You can get it as a board game or an app for Android, iPhone or Amazon devices.  There is a free 'taster' version which has lots of puzzles and will give you a feel for how it works.