I really fall in line with Collegeparentnomore on this for position players. You need to get as many ab's as possible against the best competition you can play before you enter fall ball. I have a different opinion about pitchers. The last thing you want is to be fatigued from throwing all summer in games going into fall ball. If you can find a good fit that allows you to pitch once a week and not be over extended you can continue to work out and be prepared going in. If you threw a ton for your HS team into May and then go into a full summer season watch out in my opinion. Find the right fit for you for what you specifically need. But don't go into fall baseball at the college level without seeing quality pitching for the entire summer. And don't go into fall ball at the college level as a pitcher worn out from the summer.
Your competition in the fall position players have been playing at the level you want to achieve all spring into summer. You left HS pitching took off a few months and now your facing college pitching. Not a good recipe for success in my opinion. The fall will dictate your role in the spring. JMO