You're joking Julie, yeh? We cannot imagine you travelling anywhere on your own at 15. This doesn't impugn your ability to manage matters on your own in any way but, ... well, how are your family and friends to feel when you up and leave them for distant shores?
Language? One can more-than-get-by in Ireland with English.
Some phrases for you with sound files: http://home.primus.com.au/conaill/gleann/html/frasai.html
More phrases with sound files: http://www.daltai.com/phrases.htm
'Foghlaim' is the operative word that you need, meaning 'learning'. Here are some more sites from the Foghlaim section of 'Gaeilge ar an Ghréasán': http://www.smo.uhi.ac.uk/gaeilge/foghlaim/
Slán go fóill - Take care.