If the parents are PPLLXppll, then the F1 generation is PpLl.

Say that the F1 generation is crossed with PPLL. It would be a cross between PpLl X PPLL. Then what is the F1 generation or in other words what are the different gametes I can use to make a F2 generation punnett square?

I came up with PL, pL, pl, and Pl. Is that right?

One parent (PPLL) will only have PL gametes, while the other (F1) will have the ones you designated. Good work!

Yes, you are correct! The F1 generation from crossing PpLl with PPLL would produce the gametes PL, pL, pl, and Pl. These four different gametes can then be used to create a Punnett square for the F2 generation.