Right am gonna throw in my 2p for this topic. My advice is to take up a fucking sport!

Lifting weights for the sake of it is the most boring thing known to man. Find a sport you enjoy and do that instead. So long as it raises your heart rate alls good in the hood right?

I used to train weights all the time from 17-20. Id do it for a few months see some results then get bored out my tree and stop til I got fat then hit the weights again. Then I started Brazilian Jiujitsu and Boxing at 20.5 and started MMA at 22. It was the best thing I ever did in my life. It gave me goals, made me focused, I made a ton of new friends and improved my confidence. It also improved my fitness and core strength way beyond lifting any amount of weight could ever do. If you enjoy swimming join a swim team, join a running club if you like that. Or if your super brave try something you never tried before.