I feel that someone evaluating your game and identifying leaks in it from afar is hugely beneficial. It is an almost essential piece in getting a player from intermediate to really good.
As far as getting a player from beginner to intermediate...the basic advise is pretty much always gonna be the same. Call a lot less. 80% of the bad calls you are making today should be folds and 20% of them should be raises.
Once you learn how to fold, that's when real progress can begin. If you're talking tournaments, the answer to every "how should I play this" question depends on about 100 factors. Stack size relative to blinds, stack size relative to rest of table, your table image, villain table image, villain stats, where you are relative to the bubble, board texture, betting patterns, etc. Someone teaching you the right way to analyze these factors is pretty invaluable.