FIRST: PRESS RECORD. Always record. You never know when your genius might emerge.
1. Find a song you like. It can be a short simple song like Twinkle Twinkle Little Star, or something involved like...whatever.
2. Play it all the way through with joy and enthusiasm.
2.a. If you make a mistake, laugh heartily and keep on going.
2.b. If you feel like changing tempos or switching hands or altering octaves, do that.
3. Then do it again and again with slow and fast songs, with original compositions and covers, by yourself and with others.