Can someone please check my Japanese sentences?

Question:

I am writing to a penpal. He has asked me where I have traveled. I am trying to say that I have not traveled anywhere outside of America, and that I know this is sad. I am say that I have traveled to Texas, Colorado, and Florida. Is this correct? If not, can someone correct it and break the meaning down word per word?

私は旅行でどこもにそとにアメリカに行きませんでした。旅行でテキサスとコロラド…

Additionally, he has asked me this question. I did not recognize some of the kanji/words. Does this mean I will be slow to reply, please understand?
返信が遅くなることもあることがあるかと思いますが、これからよろしくお願いいた…

If so, how do I respond: I might be slow to reply as well, I am sorry. Thank you so much for your reply :)
I am not familiar with this sentence structure! I know this a lot of questions. I truly appreciate any help,
Emily

Answer:

I have not traveled anywhere outside of America.
→私は外国に旅行に行ったことがありません。

返信が遅くなることもあることがあるかと思いますが、これからよろしくお願いいた…
→You are right. you should respond that 返事が遅くても気にしません、こちらこそよろしくお願いします。