do I need to purchase tickets online with a specific time?

You can do it online or in person.

No

Don't matter, you don't have to w8

You can purchase online or in person. No difference and no wait either way.

we buy the tickets on the spot in person.

No you don't need to

Online or in person. No specific time

You can purchase tickets online or in person

No, you can purchase tickets on site in person currently