EPALE, I started practicing functional for 2 years, and progressively I was adding crossfit exercises with weights. I have 1 year training weightlifting. the important thing here is to master the technique ... I recommend practicing a lot with little weight until making a clean movement and then going up in weight.

On the other hand to master your own weight you have to do exercises like push-ups, pull-ups, dips and sit-ups. for if strengthen the body in an integral way.