Go to the Meet & Greet board regularly and look for an announcement of a M&G in your area. Read whatever instructions are there. Usually the host will give a contact method (often e-mail) and list the screening requirements. They may put the screening requirements in their e-mail response to you if none are in the post.

My experience has been the screening is similar to the screening a provider will do before she agrees to see you. Screening is important. You don't want to attend a M&G where no screening was done. My first M&G I had to give two references from providers I had seen recently plus my TER handle.  

The hobbyist usually pays a fee to attend. ($45/$50) The fee will get you entry into the event plus a couple of adult beverages and food. There is a cash bar. It's a cocktail party type event. Mix and mingle. Every host has their way of doing things. What I have described here is my experience with the M&G's in my area. There is no business conducted on the premises but there is nothing to prevent you from arranging for take-out after the event. I have heard of these being held in private residences. The ones I attended have been in restaurants where a private area away from the normal traffic of the business is set aside for the event or where the host has rented the place for the evening and the M&G is the only thing going on there at that time.

You might want to simply read the announcement threads on the Meet & Greet board to get some idea of how the different ones around the country are done.