Attempted Introduction.

Jeg elsker gitaren (the definite article "-en" sounds a little strange in this context, and would need elaboration, like "gitaren min" - eng: "my guitar" etc. Other alternatives would be: "Jeg elsker gitar..." - as a very general statement, or "Jeg elsker gitarspill/gitarmusikk..." - both basically meaning "guitar music") men jeg spiller ikke (I think you'd need to add the word "selv" - eng: "myself" - at the end there, at least in writing).

Jeg har to brødre men nei (in Norwegian, the word "nei" can only mean the opposite of "ja". When speaking of quantity - or rather the lack of it - you'd say "ingen") søstre.

I hope this wasn't too discouraging, because I honestly think this was a very good attempt. Well done!

Attempted Introduction.

Jeg heter Jade og jeg bor i Ireland.
Jeg elsker gitaren men jeg spiller ikke.
Jeg har to brødre men ingen søstre.