What is the best thing to wear on your feet should you wear sandals or should we you wear tennis shoes

Either or is fine

Whichever you prefer both are fine.

Mostly all of the ground are either grass or pavers, so either should suffice.

I had on flip flops and was fine

Either one will do

Either is fine.

There's not a lot of walking. I wore sandals and it didn't cross my mind once!