Trying to learn English

I've already have had some English lessons, but I've never had the opportunity for a real practice. Recently, I've got acquired an American client, and I had a really hard time communicating with him. He offered to call me to explain his doubts about our project, and I lied, - saying I was sick and with had voice issues. Shame on me.
Now I'm trying. I have a to travel to England in the next semester, and now I'm just hoping I survive on this trip.

Very well done! This is pretty good. Things in green are correct, things with a line through them are incorrect and things in yellow are suggestions that I will comment on hereunder.

-In English, we have a few ways of expressing ourselves in the past tense. I had as well as I have had and I had had. Although they essentially mean the same thing, there are some subtleties in the differences. I had (past tense) is what I think of as the simple past tense. I have had (past tense meaning that in the past you used to have something that was further in the past than the "have". That is a particularly clumsy explanation, but I can't really think of a better way of saying it.) and I had had (which for me is the furthest back in the past of all of them). Although technically correct, the phrase I had had is very clumsy to read and is not very commonly written. Try to avoid when possible.

-My old high school English teacher always used to tell my class that we should never ever use the word got. She used to say that there is always a better word - so I've suggested that you do so, although what you've written is correct.

-My old high school English teacher would also tell you that you shouldn't use a comma before the word and, but many professional authors of fiction will do it. Commas put a "breath" in the sentence, so you read it with a little gap in between the clauses that are separated by the comma. When you do this with and it sounds like (for me) that the clause starting with the word and has come as a kind of after thought, but not as much of a gap as when you use ellipses.

-The American slang phrase I had a real hard time is best not to be written down! Although used in casual conversation in the US, you will never see it written down in anything formal! Also, we don't say that here in England. It's similar to the phrase for real? (which we also don't say here) which is also very slang like. Again, we don't say that in England and our equivilant is really?.

-A hyphen should be used when the clause following the hyphen explains the clause that precedes the hyphen. A colon also can be used for the same purpose.

-In English we say I have to go/travel/walk/run/fly/swim etc.

-The phrase would sound far more natural (in my opinion) if you were to take out the words in the and just say ...England next semester.

-You put no subject in the last clause of the sentence! Remember those, they are important!

Hope this helps. Keep studying hard! :)