1) Talking to people from other countries is always really interesting, there are so many questions to ask! I would ask how much homework they have, If they find their school hard, how long the lessons are? Do they find school interesting? Would they want to swap schools? Something like that. (можно не писать)
2) Working hard and reminding them of how important your tests are for your future! Because I feel like you can achieve anything if you really want it.
3)Education is really important but I feel like going to a popular school/uni does not guarantee you a successful career in the future, again, you have to work hard anyway.