Question

Czy dobrze to napisałam? Tzn. poprawnie językowo?

I would like to describe my friend, Marcelina. Her hobby is horse riding. She go to the stable with her friends, Dominika and Ewelina. Marcelina loves horses. Her favorites are Magic and Fili. Sometimes she make earings. She like watching ''Szkoła'' and ''Ukryta Prawda''. She usually listen to pop music. Marcelina is interested in painting and drawing. She find it easy. She is good at playing volleyball and handball. Marcelina haven't bad habits. She think tell a 'white lie' is OK, because the other people will be happy, not sad or angry. If she were a DJ, she would choose pop music, because she think it is a interesting kind of music and she really like it.
Daję naj. :)

Answer 1

Pododawaj końcówki "s" do czasowników, bo mówisz o 3 os. (makes, likes, listens, finds, thinks)
Marcelina hasn't got bad habits. She thinks that telling a white lie is Ok...
If she was a Dj....
She thinks it is an interesting kind of music and she really likes it. 

Answer 2

I would like to describe my friend, Marcelina. Her hobby is horse riding. She goes to the stable with her friends, Dominika and Ewelina. Marcelina loves horses. Her favorites are Magic and Fili. Sometimes she makes earings. She likes watching ''Szkoła'' and ''Ukryta Prawda''. She usually listens to pop music. Marcelina is interested in painting and drawing. She find it easy. She is good at playing volleyball and handball. Marcelina hasn't got (albo doesn't have) bad habits. She thinks telling a 'white lie' is OK, because the other people will be happy, not sad or angry. If she were a DJ, she would choose pop music, because she thinks it is a interesting kind of music and she really like it.

Ciągle zapominasz, że Present Simple ma w III formie końcówkę "s" :) No i jeszcze jeden mały błąd przy have, generalnie albo don't (doesn't) have (forma częstsza, ale amerykańska, więc ewentualnie nauczyciel może się czepiać), albo trochę przestarzała haven't (hasn't) got, która jest z kolei formą typowo brytyjską.