Should a 14 year old boy use electric or regular razor shaving for first time?

That is generally up to you. You do have to be more careful with an electric razor than a regular one though. i recommend starting off with a manual razor it should be a little irritating at first but you'll get used to it. i tend to feel that electrics leave a cleaner shave but are definitely more irritating to the skin. if you get a lot of irritation you should consider using aftershave (it stings, yes, but helps with irritation)