I need some tips for a high school wide receiver?

I am 6'2 and weigh about 170. I am going into my junior year, my soph year was my first at wide out, and I caught one td for the sophomore team. I spent most of last year memorizing the offense and learning the position. Now I think I'm ready to do some damage. My first 40 time is somewhere around 4.8-4.9, and my pro agility is 4.7, i dont know if thats any good but id like to get my 40 time to 4.5 at least. I need tips on route running and getting my speed up thank you