Traveling to your country is really expensive.

Traveling in your country is expensive.

When communicating with foreigners, you don't have to consider grammar at all. Just say it. Say the general meaning, and foreigners will get the general idea. Gradually you will get better and better. Of course, it is inevitable to make some mistakes and make some jokes. I've been there.

Love his girlfriend: I think he showed it to others, especially his girlfriend. He loves his girlfriend, so he also loves his girlfriend. No problem!