New guy really needs some HELP quick.

Good morning, I am new at this but had a hot water machine and cleaned 7-11 stores years ago. I have moved to Florida now and about finished getting my trailer ready. I sure need some advice on the best way to tie off a person on a roof and were would be the best kind at the cheapest price of gear to purchase.And if anyone could give me some hints about clay tile roofs. I might have a job to do in a gated community and I need to do a good job and not get any body hurt. I am 58 and to dam old to get around on one. The person that will do it don't have any experience of cleaning roofs but you got to start some where. If any body in the Ft Myers are can give me some tips and I am not doing it for a living just to make some extra cash. And ball park figure what is the going rate per square foot on clay and shingles I don't want to start off being the new kid and doing it for nothing just to get a job. And best place to get the chemical and it is a 30 to 40 percent right. And two bottles of Gain Ultra 64oz bottle right. I am using a air flow 1/2 inch pump and 200ft of hose, will 75 gallon total do a 3000 sq foot house. It's in Gate Way if someone here they will no the area. Here is my email  flattconst1@yahoo.com  it will come to me on my phone. Thank you very much.