What's a good time to call and actually get an answer? I've been calling for two days now and not getting an answer. I simply want to know if you're not camping is there a need to get your ticket to enter the park early or pay the day of?

Definitely get there early on the weekend. Just pull to the gatehouse and they will direct you from there. No need to pre purchase.

Not really but the earlier you get there the better. It gets very crowed with long lines from about 10am on, especially on the weekends.

You'll purchase the entrance admission once you get to the park. The attendant will tell you to go to the store to buy your ticket. I think 8 am is the earliest.