How to workout well and get abs and muscles?

Everytime I try to run the treadmill I stop in like 10 minutes. How do you keep going? It just gets boring and I dont want to do it… Also, how do you get abs? I know that sit ups are good but are there better ways? And… how do you get arm muscles? I’m 14 and I weigh 130 lbs. About how many pounds should I lift? How long and how many of each should I do a day.