First Solo travel to Greece

Hello everyone! I'm trying to plan a solo trip to Greece for this summer and since I never been there I'd love to hear your suggestions, tips and everything you can share . Basically I'd like to stay there for 7-10 days and I'd love a place where I can have fun at night with tourists and locals of course, so should be very active nightlife, but also a bit safe . I'd love to cost some of the epic constructions and archeological sites there during some days. And if possible an hotel by the beach because I want to relax also . Thank you so much in advance , feel free to suggest anything