I wouldn't waste my time on this.
It is a fantasy.

There aren't enough men out there who want to pay big money to be among 15 men and only one woman - I promise you, I know something about parties & they don't bring women big money.

You will get a crowd of men to turn up if they believe there will be a crowd of women. After the cut for the house, you won't make big money from that sort of party, but it can be fun if you are into that/ go with a friend/ and be happy to walk away with a token amount of money that might pay your transport.

Otherwise, there are small parties, perhaps you'll get 3 guys. Again they expect to pay less than if they were doing a 1 to 1 with a woman. And the organiser/ house needs paying, so it's not a huge money-maker for the woman.

Note - there's nothing wrong with parties just don't have unrealistic expectations about money. You will likely earn less than doing 1 to 1 escort work.
And finally, of course, if you are turning up alone to do a session with a group of men, how will you keep yourself & your possessions safe? You can't trust an unknown organiser.