With Pickleball, because it’s a fast pace game, it’s best to have only (1) grip for all your shots.
It’s called the ‘continental’ grip. Put the paddle in your ‘hitting’ hand, and stretch your arm out straight (ensuring you are not twisting your arm, wrist, or hand in a non-standard/normal way/position). The top edge of your paddle should be facing directly up, and the bottom edge of your paddle should be facing directly down. Another way to do this is to hold out your hand as if you are going to shake someone’s hand. Then place the paddle in your ‘hitting’ hand so the top and bottom edges are facing directly up and down