Dear Ben, (запятая обязательна).
Thanks for your letter. Sorry I haven't written for so long, but i visited different countries.
Well, I want you to come in my city because my city is very preatty. We will go to Red Square? there we will go to cafe . Its very fun. I think we will go to Gorky park. The park is very beautiful and large.
(Не знаю что написать с yours, если наешь, то напиши я переведу.
Iam waiting you in my city.
Lots of love,
(своё имя)