I just turned 16 a couple weeks ago, i have the same kinda troubles you do except ive been smoking since i was 9 and have learned tactics to work around my father and all that other shit. Theres nothing better than sittin on the shitter and smokin a bowl, turn that ceiling fan on and use a Spoofer (paper towel roll stuffed with drier sheets) I had 2 bongs 2 bowls and a chillum and blunts/papers up the wazoo, alls you have to do is find a decent place to hide them, i use a droor with a lock on it and when my dad tries to open it and asks whats in there, i just say that i locked it and lost the key, lol kinda sketchy but it works. how much u should smoke/buy depends on what ur getting, after smoking good shit for so long its damn near impossible to smoke shwag, brick. so save ur money, buy a 1/8 of dro, or the best u can get ur hands on, invite a friend over and just chill and watch half baked or harold and kumar go to white castle, but if its nice out, i walk to the driveins and sneak in with like 8 people, fun as hell. good luck to ur situation hope my advice.or story.. or what ever i just wrote helped