Hi Oceana and welcome

Your first job really should be to read the articles on the main SAAFE site, where you'll find all the basic stuff including info on safety and security, advertising, health, tax, spotting timewasters and all kinds of other bits. Once you've had a good look, you can come back over and search the forum for the specific things you want to know - the Search box is up on the top left and if you type in keywords (advertise, condoms, self employment, outcall, period are all common ones) you'll find previous discussions on all kinds of things.

We don't recommend agency work here, especially for newbies but if you decide you'd rather use one there's also a main site article on things to look out for. You don't work for them though, it's the other way round so there's no PAYE - you are self employed and it's up to you register with HMRC and keep proper records of your income/outgoings, but it's really not complicated .

'Discreet employment' isn't an offical term for anything, I don't think - I've never heard it before? One great thing about sex work is that you can fit it around any other commitments you have, so your other job shouldn't be a problem at all once you get into the swing of things.