DIY haircut advice

Hello! I want to start doing more of the haircuts for my king charles cavalier. I looked up some brushes to get like chris christian wood pin ans mars king undercoat as well as sharf thinning scissors. My questions now lie with do i need a electric clipper set? Of so which one, i do not want to spend 445 on a heniger opal if possibke and i dont mine corded.

What are some trusted video channels i can use to learn how to cut and what and where to cut, and where not to!