Man...stay the hell away from McSh|tties. It's lower than low. Lower than how low the molten magma is below the surface.
I'll start off with pay, since given your age that's probably the one of the most important things regarding a job.
The number of jobs that you can get without a high school diploma are slim, and they nearly all pay terribly. So I'm going to assume that pay isn't a big deal to you.
$6.15/hr. (minimum wage) = $959.40/mo. (not even a thousand, damn!)
$6.50/hr. = $1,014/mo.
$7.25/hr. = $1,131/mo.
$8.00/hr. = $1,248/mo.
Assuming 10% tax rate, you may get more or less depending on your situation.
For half-time work (20 hrs./wk.) just divide the monthly figures by two.
So what's left to consider? It's what people will think when you tell them where you work, or what your customers will think (if the job requires contact with people, such as retail).
At a fast-food joint, people will automatically consider you to be sub-human. Why else are you working there? No one wants to be there. This is especially true if you've been there a long time. People who work there tend to be fairly dumb (it's mean but it's usually true!).
The customers are condescending, assuming you're stupid. It doesn't even matter that people who go to places like that tend to be poorer than average, since fast-food joints are cheaper than many other restaurants.
Jave joints and other restaurants are better (perhaps because the prices are higher?). The customers are nicer to the workers, and don't necessarily assume that the workers are stupid.
Retail might be a good choice for you, because most customers will assume that you must know more about the merchandise than they do. They'll look up to you. It's the power of knowledge at work here. This is especially true with technology.
So basically, if you must work in a restaurant, get a waiter job (wage sucks, but tips more than make up for it), or deliver pizzas (again, tips make up for it). I'd recommend retail myself. I'd try to get a commission job if I were you, because then you'd make more money on busy days.
Plus, I doubt a woman is going to be impressed if you work at a fast food joint, unless she's either A) a trailer trash b|tch, where three or four generations share a trailer (I once met someone like this!), or B) the daughter of a welfare mom. And I doubt that you want either.
So think hard about the social stigma and the consequences if you start to work there.
My $.02,
Ben