Tri-Star stawberries are day-neutral so will fruit from July until heavy frost. Ever-bearing ones fruits mostly in June.
Corn - try growing Grant (sugar enhanced); Speedy Sweet, and Extra Early Supersweet.
Peppers grow best in somewhat acidic soil (5.5-6.5). They need lots of calcium for healthy fruit and magnesium for leaves.
These are notes I made about gardening. See more gardening notes