What is baby shower protocol?

Do we have to play games?

If I have it at a restaurant does the host need to pay for everyone's food? Or can we just have appetizers and cake?

If I have it at my house can we just socialize, have appetizers and cake then open presents?

Do we have to decorate?

I'm not big on the games and I have a little social anxiety so I really dont want to make a big deal of it but I do want to have one.