Football’s timeline is accelerating, but it is nowhere near what is discussed here in other smaller sports. Much of football recruiting still starts with tape, and there is really no substitute for your son laying out some good tape against quality competition. Once your son is seeing multiple varsity reps, get a hudl account and start cutting up short (3-4 minute max) highlight tapes showing him doing varied and basic things against the best competition he faces.
As far as camps, top of the food chain kids (mainly kids aiming at top half of P5 conferences) might start in the summer after freshman, or more commonly sophomore, year at a few select large school camps. Lots of kids hoping for Division 1 will do SPARQ &/or Rivals following their sophomore year as well. SPARQ and Rivals are good because they are the first shot at relativley accurate and unbiased measurements (height, weight, 40, 3 cone, vertical, etc.) In addition, SPARQ and Rivals have elite camp off shoots where they invite a certain percentage of the best performers from the regional camps. These can be very important in elite level recruiting, because it is one place where college coaches know a particular recruit will see really athletic competition. Junior spring, and then the camp circuit in that summer, remains the biggest piece of the recruiting puzzle. Usually, the tip top kids will have a good idea of their position at various schools by the time junior camps roll around. For the remainder of the kids shooting at the bottom half of D1 or the smaller divisions, a whole lot of decisions get made during the junior camp circuit.
For skill position kids, 7 on 7 leagues are becoming pretty important as well. This may depend on your geographic area, but in bigger football states there will be plenty of 7 on 7 leagues that will be playing through the summer. Some leagues are made up of kids from the same high school teams, others are more like a travel baseball team and have kids from various schools. The best of these leagues are followed closely by the major recruiting services (247/Rivals/Scout/ESPN) as well as a lot of stringers for college coaches. My son is a lineman, so he did not do the 7 on 7 circuit, but based on skill guys I know the timeline is similar to the camp timeline. The best kids are playing after freshmen year, and then kids kind of filter in over sophomore and junior summers.
The best thing to do for your son right now is to encouorage him to lift and get stronger. Work his technique relentlessly. If you can, and your kid really wants to point towards playing in college, next fall I would look for a local gyn/trainer where he can get some specialized instruction in his presumptive positions, or at the very least a place where he can get some speed work/agility work done. I do not know the area you are in, or the level of the high school at which your son will play, but I can not stress enough that most kids with the size and athleticism to play in college, particularly at the D1 level, have truly horrible technical skills. This is mostly because they are athletic mismatches for the competition they face in high school and are not really required to work the finer points of the game. And then they hit the camp circuit and see kids who are more of a match for them. Without exception, the kid who is technically sound is going to show much better in those situations.
Good luck!