Hey Jack, Welcome to the forum. I'm Dan from Southern California.
for your first question, What kind of wood and thickness are you using, and what kind of blades? If you are using a reverse tooth blade, the lower reverse teeth will cause the board to bounce up and down if you don't hold the board down firmly. For this reason I recommend beginners start with a non reverse tooth blade such as an Olsen skip tooth.
For your second question, cut to the end of the v, then back out a little, turn the wood so the teeth cut into the waste then back the backside of the blade into the corner then turn the board into the line. I hope this makes sense to you!
