Semi-formal attire is required. No sneakers, t-shirts etc. A strict dress code will be enforced.

I know yeah probably supposed to wear like a button up dress shirt.
But instead of sneakers. what else is there? All I can think of is like nice dress shoes, is there an alternative?

Loafers.

you could wear something like sperrys they are a little more casual but still dressy

loafers/dress shoes + dress pants/chinos/jeans + dress shirt

do yourself a favour and don't even consider anything else

what is this