YOU SAID:

i have a girlfriend and she likes to go to parties

INTO JAPANESE

私はガールフレンドがいて、彼女はパーティーに行くのが好き

BACK INTO ENGLISH

I have a girlfriend and she likes going to parties

INTO JAPANESE

私にはガールフレンドがいて、彼女はパーティーに行くのが好き

BACK INTO ENGLISH

I have a girlfriend and she likes going to parties