Исправьте, , ошибки. заранее . this summer i was in the city. in june, i went to the festival green and there had a great time with your friends. at this festival, we listened to good music, participated in kolorfest and swam in the lake. every night i went out with friends, we were having fun. and in july, we went to rest with the parents of the krasnoyarsk sea. we swam in the sea and sunbathing. unfortunately, it's time to finish. please tell us how you spent those summer holidays? what was the weather? what is interesting to see in the meantime? with best wishes, vika.

This summer I was in the city. In June, I went to the Green festival and I had a great time with your friends there. At this festival, we listened to good music, participated in KolorFest and swam in the lake. Every night I went out with my  friends, we had fun. 
And in July, my parents and I went to the Krasnoyarsk Sea to rest a little. We swam in the sea and sunbathe. 
Unfortunately, it's time to finish.
Please tell us how you spent those summer holidays? What was the weather? What was interesting to see in the meantime? 
With best wishes,
Vika  - точку не ставим

Не забудь поздороваться))) И абзацы оставь, как у меня (это части письма)

I spent this summer in the city.In June I have been to the Green Festival and had a great time with my friends there. We listened to good music, participated in ColorFest and swam in the lake. Every evening we were out and had fun.
In July we went to the Krasnoyarsk Sra for the vacation. We swam and sunbathed there. Please tell me how was your summer vacation. What interesting have you seen?
Best wishes. Vika.