Can 15 year olds work as a grocery clerk or waiter at a restaurant with papers? What are all the rules that apply e.g. how many hours/week?

It really depends on the state. Some states are "Right To Work" and in those states you can begin working at 14 or 15. Although you can't work over 20 hours per week or past 7pm. Also if the store is not union they can also pay you lower then federal minimum. The goverment might of changed that in the past couple years but it still might be a problem. Some states will only let you work during the summer as well. Also I'd go for the grocery clerk job. You only have to deal with crappy customers for 3 minutes instead of 30. You can check out http://www.dol.gov/ to find out more. Good Luck!

In Australia you can indeed do those jobs. Other countries I am not sure about.

Yeah..but i'm pretty sure that a 15 year cannot work before 7 am or after 7 pm unless it's a weekend or summer cause they can't work after 7 on a school day or whatnot

It depends on where you live. In the US, a 15 year old is allowed to work as long as they've obtained a worker's permit and as long as they follow the guidelines (which vary a bit by state). There are certain positions you won't be able to fill like kitchen positions or deli positions because you have to be 18 to operate most of the appliances. Also, you may not be able to wait tables at an establishment that serves alcohol since you have to be a certain age for that.