I'm coming the week of December 13th 2018 to Dec. 18th 2018....how much is it to get into the park for 30 or more ppl

Parking is not free, and please call the park for group discounts

$ 25 parking per car. Tickets prices vary depending on the day of week and how far in advance you buy them... I don't think the have discount for big groups.

You really need to check with the park. Chances are you will pay the same per day per person as everyone else.