3 questions for entrepreneurs

Hi everyone!
I’m a high school student interested in International Business, and I’m doing a small research project about international business expansion.

I’d really appreciate answers from entrepreneurs or business owners. Just 3 quick questions:

1. What was your biggest challenge when entering a foreign market?
2. How did you choose which market to enter?
3. What skill is most important for someone working in international business?

Thank you for your time! Your answers will help with my student research.