C.Y.
I had two preemies...a boy at 30 weeks, and a girl at 27. During the first two years it is improtant to remember that he is 2 months younger than his actual age. For preemies you also want to give them a little extra range to reach their milestones. My son still wouldn't sit until he was more than 8 months old. Just encourage tummy time to give him the opportunity to develop those neck and shoulder muscles. It is helpful if you are on the floor with him also to keep him interested. Keep in mind that even a few minutes is better than nothing...both of my children detested tummy time. As far as the feedings he is probably eating what he needs for his size and weight...as long as he is continuing to thrive just follow his cues. Check with his doctor about starting solids...some encourage it while others prefer waiting for their adjusted age to catch up.
Are their any programs in your area of other parents with preemies? you can check with the nicu they usually can give you oodles of info. Your pediatrician or the local school district may have some also. most areas have great parents as teachers programs. The first year with a preemie is, in my experience, very difficult. Very rewarding, yes, but rough on your nerves. after the first birthday it tends to get easier.