Is it just a raclette set or does it have a hot stone for cooking on top or other fancy functions?
The traditional way is to serve the raclette with charcuterie and new potatoes that you pour the melted raclette on. If you have a hot stone on top, you can cook thin slices of fresh meat and vegetables (eg mushrooms, peppers, onion, courgettes) as well. I slice the meat and put it on a plate on top of a bowl of ice to keep it cool. I would just keep it simple, don't try to use it to cook anything fancy. The fun is everyone cooking for themselves.
If you don't have a specialist cheese shop nearby, Waitrose and some branches of Tesco sell sliced raclette. You can also get it in Costco and online eg Amazon. I believe Lidl have it sometimes too.
You can use other cheeses if you can't get raclette eg cheddar, gruyere, Jarlsberg, St Paulin, mozzarella, gouda. I would say Jarlsberg and St Paulin are most similar to in taste to raclette. You could probably use it to cook halloumi too but I've never tried it.
If you do find raclette, I strongly recommend using it in cheeseburgers instead of plastic cheese slices!