What can be causing my 2002 hyundai accent to not start or stall at stops?

I have a 2002 Hyundai accent that has stalled a few times when I have been at a stop light and it wont turn back on for 20 minutes. other times when i try to turn it on it just wont start. it is getting very frustrating and i would like any advice!|||Dirty fuel filter or clogged injectors. Plugs may be old.