Czy popełniłem błąd?

Witam serdecznie, piszę właśnie wypracowanie, a w sumie list (2kl.gim, podstw poziom). Czy jest w nim jakikolwiek blad?

Oleśnica, 28.11.12r
Hello!
We’re in the competition and we’re planning your days in London. There are three of us in the group: Justyna, Martyna and Mateusz. We’re both 14 years old. We’re from Oleśnica, and we go to gymnasium number 3. We’re native polish teens. We teach two languages at school: English and German.
Our city is a great place because you can have fun here. You can go to the disco, cinema, sports center or museum so everyone can find here something cool. Justyna is into sport, so you can go with her to the skating rink or swimming pool. She is a really good skater! Mateusz is keen on history. He can go with you to the local castle and the city gate. Martyna love music. You can go with her to a concert or visit local music school. We can go for a good pizza, because we have got a lot of pizzerias in Oleśnica. We know also snack bars from China and Turkey.
Even if we lose it we are waiting for you!
Best wishes,
Martyna, Justyna and Mateusz!