To contact experienced bodybuilders, you have to write to them directly. But it seems to me that you can cooperate not only with famous bodybuilders but also with beginners who often take part in different competitions. There are a lot of bodybuilders now, and most of them have experience in competitions. I like to train in the gym but never thought about becoming a bodybuilder. Moreover, I also take https://purerawz.co/product/yk-11-myostine/ to speed up muscle growth. But I only do it to make my body look how I want it to.