wow, thats alot of questions, sounds like your entirely new to this shit. So heres some basics for buying. A 20, or twamp is a gram, a dime is two bowls, and a bowl is the usual amount u smoke in a pipe. gram is around 20, dime is 10, bowl 5. This is usual. Then an 8th is 40 some, a quarter is around 80 and so on. Saying O, like oh, meens an ounce.

I wouldn't grow yet, but weed stays detectible for around 2 weeks, to pass a test, add warm water to dilute the piss, best weed is extremely hard because there is alot of different personal tastes! check out overgrow and seedsdirect