Ain't string trimmers a bitch? (but beat the alternative, that's fer sure.)

I've got a Weedeater Featherlight. It won't start this spring, for the first time. I suspect it just needs a new sparkplug and cleaned up, but I don't know how to do that. I can change the plug, but don't know how to gap it, and don't have the confidence to follow on-line instructions on using carburator cleaner to clean up the little engine. The internal combustion engine is a mystery to me and I can't tell a carburator from an air filter from a gas line.