Food stamps aren't cash. :) You are also limited in what you can buy with food stamps, though these limitations sometimes vary from state to state. For example, when I was on food stamps, I could not use them to buy toilet paper or other household necessities- though I could use them to buy junk food like candy bars, chips, soda, etc.
As for how much you get, this varies WIDELY from person to person. To get food stamps, you have to apply for them, and the amount you get depends on your expenses (kids, rent, etc) and your income (as well as the income of your spouse if applicable).
To get food stamps, you must go to your local social security or welfare office. If you don't actually need food stamps and just want to see if you qualify, though, this will be a futile pursuit. In every place I have lived, SS/welfare offices are crowded and it can take literally all day to get in to see someone. Sometimes the staff are rude and horrible to you. Overall, getting food stamps is an unpleasant process.
For more information: ww.ssa.gov/pubs/10101.html
It's hard to say how much you get, but if you don't have kids, I highly doubt you'll qualify (not sure how it works in each state) also, if you have a job, I believe that excludes you as well, but I could be wrong. And NO you do not get cash, you will get an EBT card and it's only for food. Which does not include fast food.
The website I linked also has a link to a web tool you can use to find out if you're eligible: ww.snap-step1.usda.gov/fns/
Though it is not necessarily 100% accurate, I used it myself and it said I did not qualify because I'm childless. :)