Early May (until the 16th), the park opens at 5:00 AM and the first shuttle runs from the Visitors' Centre to the tip at 6:00 AM. Traditionally, people start their day at the tip to see what has blown in overnight. However, the best place in the park often depends on the overnight weather. If Ohio was clear-skied but there was cold rain over the lake, the tip is unsurpassed. However, with gentle breezes from the south, you might find better birding farther north in the park.
There are a number of guided hikes, but they tend to fill up fast on the weekends. Whether or not they are worth the price depends on your comfort as a birder. Or your comfort in flagging down a passing stranger to help you. It can be quite populous in the park, but almost everyone is a birder. Most are friendly. Your mileage may vary.
From the 17th on, the park doesn't open until 6:00 and I don't know if the shuttle runs from 7:00 or from 10:00. Not that you can't walk to the tip from the Visitors' Centre. And the guided hikes are no longer available.