One thing I've learned about maters is that for me they do best when they don't get FULL sun especially at the height of the summer. I plant them in the backyard so they get most of the early morning and afternoon sun, but not much of the evening.
As for peppers, they can tolerate full sun. You can either prepare a large area of soil, or you can prepare just the hole for each plant. Remove the soil where the plant will go, mix some of the soil with fertilizer, potting soil and then use that new soil to back fill.
I like to start from seeds with most everything. But you could start off with seedlings too.