Do we have to buy the tickets online or do we pay on the aquarium? because we want a pass for every single thing on the aquarium there are 3 adults and a 11 year old.

You can do both online and on site

You can do it at the gate

Either. You can purchase an all day adventure pass to ensure you get the full experience.

Pay there

You can do both I think I didn't buy tickets cuz I went later and all of it was closed it closes about 7:00 all the rides but it stays open until 9:00 in the restaurant

I bought ours online. I think there's deals online that you won't be able to find when you get there. The ticketing booth was open. There's a fee for parking there too.