Looking for Safe and Legal Supplements

Up until recently I was not really worried about what was in my supplements, but I am going to be playing varsity football this year and we do have drug testing in the school district. I guess that a lot of schools do as well and of course I know that a lot of supplements work more or less the way that steroids too. Most of the fitness supplement reviews that I have found only talk about the actual product and they are really mostly interested in bodybuilding. I want to be strong and fast. I am five foot nine inches tall and 148 pounds, I am going to either be a defensive back or a receiver.