First off, we recommend all new clients & providers read the self help section (link by the life preserver at the top of this board)... then read back on this board for several pages at least. You will process this information from a different point of view specific to your circumstances. And it's FREE!
I strongly suggest you learn about the 2 call system, use separate email & phone for 'work'. You should not offer services from the same location you sleep & live. I won't say it's never done but there are all sorts of risks with doing so. I know a few who do but have a strong cover story & limit their traffic.
You need to learn screening... Not a topic for an open forum... but perhaps some gal will mentor you. You might want to read the legal board as well... there's a report of a bust currently there.
As for donation... there are a few things which affect what clients are willing to pay. (This is my personal opinion) I apologize if this seems crude but we are talking about physical things here.
Looks. The more "attractive" a provider, the more in demand she'll be. There's a good thread on the General Discussion Board about attractiveness. There's not a lot any of us can do about genetics but keeping in the best shape possible does matter.
In the end, it's SERVICES that clients are compensating for... less attractive gals have to try harder. You can not tell from ads what services are really offered behind closed doors. I suggest you pay (just as a guy would) for a month's VIP. Do a market survey. Read reviews of your area, tally the prices & services for gals of your body type so you know your market. At the end of the month, cancel your VIP. {Providers with reviews can link their TER profile & get free limited VIP... but you can only see your own (full) reviews, not others.}
You'll need to advertise & should have a web site.
You will need pictures. Yes, they must be real & of you. You can blur or hide your face. While some use professional photos, GOOD Quality digital is within reach of non-pros these days. I look for a mix of views from all angles. Various dress & undress, poses & props. Believe me when I say, before I arrive at your door, I want to know what you look like naked. I think it requires 6-12 frames minimum. With a larger gal... if she hides her belly... unlikely I'll call. Photos need not be totally explicit, however.
It is OK to pick your best images... and it is my observation that breasts are largely "fatty tissue" medically so a BBW gal will likely be an asset to show off.
I hope this helps & good luck.