Welcome to AM sully... I too play DE, currently at the JC level. I was about your size coming out of HS as well.. I do not know much about the bigger-faster-stronger program. But from what i can see, this program is ideal for someone who is just beginning to train hard, and learn about sport performance/sport specific training techniques. So i guess i cant really give you much advice on your training program, seeing as you are already dedicated to BFS...
As for your diet, its pretty simple.. You are going to be playing on the line. Therefore, you are going to need as much mass as possible. I would not worry about adding a little bit of body fat, along with the accrued lean muscle mass. Your maintenance calories are probably around 2800-3000. So, you must make sure that you are always taking in at least 3500 cals per day in order gain weight. Try to consume about one gram of protein per pound of body weight, i would say that if your goal is to weigh 225 then get 225 grams of protein per day..
Yes, you can begin supplementing... You are an adult, and can make your own decisions.. But, don't go listening to every f@cking d!p sh!t that that tells you phera this and drol that...
The honest truth sully is that you can legally obtain what are in essence legit designer st@roids. But i can tell you from experience, it isn't worth it... not at your age, with limited training and diet experience... from most important to least important goes: DIET, TRAINING, SLEEP... Once you have these things established then and only then do i recommend that you begin supplementing with anything other than protein, and/or weight gainer shakes..