Hi, Stacy. There are no exact rules on what to feed your child or when. Since he's got his first tooth rather late, he's probably not ready to eat much table food. That's OK! You can keep on grinding up his food as long as he needs it that way. You don't have to rush into food that might not be safe for him to put into his mouth.
You don't have to worry about choking as long as you keep giving him foods that are good for a baby who has only one tooth. You can grind up a variety of things, or you can even cook vegetables until they are soft enough for your son to gum them down. Peas are an excellent choice, which you've already made. If he likes peas, he might like green beans, too, as long as they are cooked until they are soft and almost falling apart. Bread is good, even breadsticks as long as they are not too crunchy; cheese such as chedder or white cheeses are good finger food, too. Cooked apple slices without the skin can be nice (steamed or blanched until soft). Potatoes that are sliced in wedges and baked soft, not crispy, are good, too. You can bake hamburger patties and cut them into small wedges if you're not a vegetarian. I recommend leaving out the bread because that's a lot for his little mouth to process at the same time.
I've never been much into schedules. A general routine is good, though. It sounds like he's not ready to follow a routine of just breakfast, lunch, dinner, and snacks just yet. Remember that baby will get hungry more often than an old child or adult, and keep giving him good food every 4-5 hours or as he needs it. When he starts talking, he will start asking for it instead of grunting, crying, etc., so you will have more clues about what he needs.
Don't worry about the sippy cup yet. Offer it to him a couple of times each week; he'll show you when he's ready. You might have to get one for yourself and show him that you like drinking out of it; he might start to like the idea of gradually leaving the bottle behind. He still needs to suckle; remember that in other cultures, children breastfeed part of the time up to three years and even beyond! So don't be surprised if he still wants his bottle for several more months.
Enjoy him, and keep discovering the wonder that is your growing baby boy!
Peace,
Syl