How can I keep myself motivated?

Hello, I'm currently 15 and have a list of goals I must complete, a few of these are (note: all goals have smaller achievements, I guess you could call them way points): Greatly increase my core strength- Do a handstand, do handstand push ups against a wall, do handstand push ups without any support.

This is just one example, probably one of the least important of my goals but it is one, my only probably is keeping motivated. Please help me to stay motivated I am about to write out a check list of sorts to keep track of these goals, what else can I do?