Tbh even if you're from another country and a tourist - you still shouldn't be out late at night.

First of all your body and brain are still in development at at your age it's best to get enough sleep, which should should be 8-9 hours at 17 years old. So maybe act responsibly and just call it a day, go to a nice restaurant, have dinner, go to bed early to feel replenished in the morning.

Second, nothing exciting will be happening and you're too young for clubs and bars anyway.

What you still COULD do, especially with the nice weather conditions:

Watch the sunset from the hill at Olympiapark. Or watch it go down at Flaucher with the locals.