If you aren't too clued up on what you are looking at, take it to a decent mechanic and have it fully serviced.
If you are really keen to have a go, get a workshop manual and check the fault diagnosis guide and go from there.
Id go the full service to start with and then you can work on learning to work on your engine yourself. Get a workshop manual and give it a read and get an idea of what you are looking at.
Sounds like the carb though, and probably be best to get a good used one or even better a new reco version, and you can cross it off the list for potential drama for the next few years.