How can i get a 6 pack?!?!?

ok. im 13 nd im not tht fat (weighting around 85) but i hav a lil belly fat lke when i sit down. i wnt to get a good 6 pack. i work out at the gym once a week wit my baseball team but i wnt to kno wat to do at home to build tht lil belly fat nd to get ripped abs. (im basically askin for a video to look at on utube)