Dear Tom,
Thanks a lot for your letter! It was great to hear from you again! Sorry_I haven't written for so long, but I have been busy with my exams.
Well, in your letter you tell me about how you spent last summer in the mountains. Actually, I can say that active holidays are the perfect way to rest. I try to take active holidays every season. As for me, the best company to spend active holidays with is my family. I dream about parachuting because it is the best way to feel yourself free.
I want to know more about your school project. Have you received a mark for it? Were there any purposes for writing about events of the past of your country? Which events you have written about? Anyway, I have to go and get on doing my homework.
Hope to hear from you soon!
Best wishes,
Nastya  :)

Practise for my exam: writing an informal letter

Please, help me with my task! I have written a letter and now I wanna know are there many mistakes or not:)
The task is:
You have received a letter from your English-speaking pen-friend Tom who writes:
Last summer my parents and I went hiking to the mountains. We spent the whole week together and enjoyed it very much. How often do you take active holidays? Who do you think is the best company for you? What extreme sports would you like to try, if any, and why?
Last month our English class got an interesting project. We wrote a paper about interesting events in the past of our country …
Write a letter to Tom.
In your letter:
- answer his questions
- ask 3 questions about his project paper
Write 100-140 words.
Remember the rules of letter writing.

My response is:
Dear Tom,
Thanks a lot for your letter! It was great to hear from you again!  I'm sorry that Sorry, I haven't written for so long, but I have been busy with my exams.
Well, in your letter you told tell me how you spent last summer in the mountains. Actually, I can say that vacations active holidays are is (you need are because vacations/active holidays is plural) the perfect way to rest. I try to take active holidays every season. As for me, it seems that the best company for vacationing spend active holidays with is my family. I dream about parachute jumping (or you could say "parachuting") because it is the best way to feel yourself free.

(Make sure a new paragraph starts here because you changed the topic.)  I want to know more about your school project. Have you received a mark (You could say "grade.) for it? Was Were there any purpose for writing about events in the past of your country? Which events  have you written you have wrote about?

Anyway, I have to go and get my homework done on my homework.

Hope to hear from you soon!

Best wishes,
Nastya

Corrections in green

Explanations in orange

Overall, a nice job!  Keep it up!