Help Soil prep for next year?

First time growing outside. Anyone got any advice to prep soil for next year. Where I’m about to grow theirs grass so I’m guessing I would have to add compost, worm castings or topsoil? Looking to grow peppers and tomato’s

First step I'd say would be to cut the grass as short as possible, but leave the clippings on the ground. Then cover the area with a few layers of cardboard to kill the grass. Then cover that with 6-8" of compost and/or topsoil, followed by a deep layer of dead leaves for mulch. By spring it should be ready to start gardening in.