Does a centre parting make people(teenagers) look older?

It can make you look older, but having a center part is probably the most original you can have your hair right now since most people don't do it as much anymore. If you look good with a centeral part, keep it the same. If you feel it's time for a change and want to look younger (although not garunteed) then get a side part, then if you like it make a step further into side fringe. Take steps though so you know if you like it or not.