I started with a crappy weight training class senior year in high school. Was weak as hell and yeah, the teacher wasn't much help. In college I started working out more, but engineering major didn't leave me with much free time to get to the gym regularly. Ended up going maybe once or twice a week, but I got better about it towards the end.
Now that I'm working I try to get to the gym at least 3 times a week, and try to hit 2 muscle groups per workout, with some cardio and ab work thrown in as well. I can't say I'm making incredible gains (doesn't feel like my bench has increased much at all in the past year, but I'm incorporating more different exercises now), but I am maintaining a good level of fitness. Going to try to really keep track of how much I'm lifting and push myself to do either more reps or more weight with each workout.
I was also a bit of a momma's boy coming up (raised by my mom, and our household was me, her, my grandma, and my aunt!) but I think I turned out alright... haha.
But anyway, I think it's a lot easier to get into bodybuilding after highschool anyway, just because by then you'll have a lot more access to gyms (whether its through money for membership, college access, or just more knowledge about how to put your own home gym together).