No, you do not need your own flat to start. Outcall (visiting somewhere), booking somewhere like a cheap Travelodge room, or using someone else's place are all perfectly viable until you can see if you want to go the 'own flat' route.
"Where would I look, if I were looking for someone like me?" Look there, and ask questions of people already working there.
You're doing some of it: research. A 'I don't care if I lose this' pay-as-you-go mobile, just for work (this means no 'mum' numbers in the phonebook as well). Virgin have been selling a perfectly fine Nokia for ?19.99, bundled with ?70 of calls - particularly if you've already with them, that's a bargain (you can use the credit with any Virgin number). Someone to call / talk to about the work.
Like the ability to take incalls, they can help generate work, but you don't NEED them. You do need to think about things like 'do I want to show my face' now. Speaking of which...
Decide on as many of your limits and boundaries, sexual and other, as you can think of before you're asked about them / pushed towards them.