I urgently need to know if everything is correct. Thank you very much for your help!

1)I use the computer three hours a week on average. I usually use it to play computer games, surf the net or do some school research.
2) I sometimes download and save files from the internet (onto my USB stick).
3) My parents believe that spending too much time on the net is bad for me.
4) They would like me to concentrate more on learning school subjects and practicing sport.
5) My mum uses the computer to improve her knowledge of English and to plan her trips.
6) On the contrary, my dad uses it to type his newspaper articles. Finally, my sister uses it to carry out school research as well as to listen to music.

1)I use the computer three hours a week on average. I usually use it to play computer games, surf the 'net, or do some school research.

2) I sometimes download and save files from the Internet onto my flash drive.

3) My parents believe that spending too much time on the 'net is bad for me.

4) They would like me to concentrate more on learning school subjects and practicing sports.

5) OK

6) On the other hand, my dad uses it to type his newspaper articles. Finally, my sister uses it to conduct school research, as well as to listen to music.

Based on the information you provided, it seems that everything is correct. You use the computer for various purposes such as playing games, surfing the internet, and doing school research. You sometimes download and save files from the internet onto your USB stick. Your parents believe that spending too much time on the internet is not beneficial for you, and they would like you to focus more on learning school subjects and practicing sports. Your mom uses the computer to improve her knowledge of English and plan her trips, while your dad uses it to type his newspaper articles. Your sister uses it for school research and listening to music.