Why does my breaker trip when I turn a light on?
If you're saying that the breaker pops when the switch it turned to the 'on' position and nothing is in the socket, it is possible if you had the 'hot' on one connection and 'neutral' on the second connection of a single pole switch, that every time you turn the switch on, you're effectively touching hot to neutral, causing the breaker to trip.

If this is a new leg/pull/circuit, I'd look for stripped sections. Otherwise, this sounds like either the socket or the switch are not wired correctly. I'd assume that something is wired hot to neutral off the switch.

Otherwise, you probably have a short somewhere between the socket and the switch. I would check for anywhere wire could be stripped unintentionally:


Knockouts
Corners
Anything that is 'squeezed' into place
Staples (especially non NM rated staples)
Bored holes in studs, joists, etc.


Also, there is a slight chance that the breaker is old and needs to be replaced. It's rare, but I've seen breakers that fail, and can be reset.

I would be surprised if going to a new GFCI socket or breaker resolves this issue.