Hello!
You don't pay, if you are in the UK they get their fee from the employer, when they successfully place a candidate in a job.
There are standard high street recruitment agencies, eg office angels, who hire for lots of general roles such as office admin, drivers etc. They will also have more specialist local roles sometimes.
There are also specialist recruiters who work within specific industries. You can find these online, they may not be physically near you but worth speaking to as they may still hire in your area.
It's worth contacting both types, you can speak to multiple agencies to give yourself the best choice of jobs. Go via their websites and send your cv along with an outline of the type of job you'd like, what level, location, full or part time and salary.
Usually they will phone you back and invite you in to meet one of their staff, this is a chance for them to understand what your requirements are, and to see that you are well presented, articulate etc (they don't want to waste their clients time by sending lots of unsuitable candidates)
Then, if they get a job in that's suitable for you, they'll phone you and discuss it. If you want to go for it they'll set up an interview for you, and help you prepare for it.
If you get the job, great! If you don't, they'll continue looking for you and phoning you with opportunities.
Good luck!