A few thoughts.
I think Plazma is an excellent product for just about anyone. I use it every day. But I suspect that at your age, it might be difficult to budget for that, So I would just say that including some sort of workout nutrition would be a really good idea. You can look at the ingredients and macro breakdown on the Plazma label and try to get creative. Anything you come up with on your own will be a lesser product, but that’s not a big deal as a beginner. Lots of things will work just fine for you at this stage.
I wouldn’t waste my time with glutamine, and you should eat well enough that multis aren’t necessary. I honestly think multis have the potential to do more harm than good. I used to think that there was no possible harm in taking them, but I’ve been convinced otherwise over the years. I do not believe one should supplement with everything ‘just because’. If you have particular deficiencies, address them. But the shotgun method that is a multivitamin is a poor idea.
Honestly, you’re not starting in a bad place at all. Your lifts are well above what mine were at that age. The best advice I can give you that I think will be useful for many years to come is what Yogi alluded to, which is avoiding the process of bulks and cuts. Lean gains are the way to go. Over a long time, you can get progressively more muscular without increasing your bodyfat percentage at all. Don’t go on cuts for months at a time, and don’t eat everything in sight for months at a time. Just follow a healthy diet like the one thepwnisher suggested, and lift consistently. If you start doing that now, you’ll be in an incredible place by the time you’re in your early 20’s, if not sooner.