I guess you are quite young so you will probably get away without having a hangover because if you had to ask either you haven't drunk before or you haven't had one. Believe me you can certainly tell if someone is hungover, especially parents. Even if you are not hungover you can still be really tired and have the smell of alcohol on your breath if you have drunk alot. But once again if you are young I doubt you will get enough booze down you to get into that state coz you would probably need at least 8pints of beer or around half a litre of spirits (thats around 20 shots) like vodka, whiskey, etc. to get into that state.
It is very easy to find you.
Yes. They'll be able to smell it on you for a start!