Translation of Slovenia in Spanish

I would like to know if Jack is interested to join us as well. Shared learning is called Tandem. I'm coming in 2 days to Spain. I will pay for the study costs of my daughter, and I assume all other costs as well.
You have to be careful when you go on summer vacation. There are many dangers but the most dangerous one is the sun itself, because if you're not careful it may harm you. People underestimate the rays.
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.