A good way to check your grip is to hold your paddle shaft so it sort of balances on the top of your head (hard to describe w/o demonstration!). Your elbows/ arms should be making right angles. This is the "paddlers box" and is maintained with all strokes.
A forward stroke should begin at the bow by your feet (again weird to describe and not demo
). A proper forward stroke while maintaining the "box" has to employ the torso.