Verb conjugation of "swell" in English

I've met the owner of Dessarmile, who has also already written you (after you came back from Thailand). However, he does not speak Spanish and therefore I do not think that they can be good friends.
We have learned that some tenses, such as Present Tense are easier and not as complex as others. Is that right? In my opinion, tenses in English are much easier than in the Spanish language.
Have you ever visited the U.S. before and if so, where have you been in the U.S.? I've been travelling in California, it was very amazing. We have traveled by car. Here are my corrections.