I have a couple of questions about how to shape and glass this boards, what this man put as filler at the end of the video? https://www.youtube.com/watch?v=B24IadaxH2w and refered to the epoxy resin, u must add a kind of catalizer like in the polyester resin? or something like that? sorry if this topic shouldnt be here im novice 
Epoxy resin is usually a 2:1 mix of resin to hardener. Check the label. The video shows him sealing the blank with spackle at the end.
The filler used at the end is spackle the stuff you use to fill small imperfections on dry wall. I’m not sure but think there are better fillers used now. Also the foam used by most shapers is also of a better quality so less filler would be required. Check out the Resin Research web site for information on mixing epoxy resin. RR is a go to brand for many board builders.