Hi Ben,
welcome to the forum. I've just posted in another thread about the course I completed last summer in West Yorks. I was a bit apprehensive but the tutors and other potential referees were great. The ages ranged from approx 14/15 years old to a 60 year old, and was a mixture of youth(teens), through 20's, 30's, 40's, a couple of 50's and a 60 year old. So you get the full spectrum. The course was presented in a fun interactive way and no one made fun of if you if you got it wrong, because everyone was there to learn. On the course, we were given a referees wallet containing the red and yellow card, a pencil, teamsheet and a whistle. After that you have to provide everything else yourself (Kit, boots etc). Once you've passed, join your local referees association and they'll help you with advice, games etc and let you know how to progress through the ranks.
Regarding the first aid course, i can't answer that, but i've passed basic 1st Aid, and the main advice they give you is to make the injured person comfortable and seek medical help straight away. From what i've learn't, there'll nearly always be someone there more qualified than yourself to treat any injuries, so i wouldn't worry too much about it, but its obviously very good to have/know.
I hope that you enjoy your course, good luck and keep coming back to the site, as you'll learn loads (like i have) reading the answers that other, more experienced refs give to various situations.