Where do I pay? Online or in person there? And is there a long line of cars?

Pay online and either print out on leave on your phone.

You can either buy a ticket online or pay cash when u get there. And the lines are usually long on the weekends. I just went last night and the line was rapped 3 blocks around the corner. I would pk snacks if I were u

It's easier to pay online and when you get there, there just scan the receipt from the email they send to you. Google Merriweather Columbia and you can pay on the website.

I think they prefer that you pay online, so they can just scan your receipt.