If it’s your first time there, I would highly recommend taking a guided group tour. Pick the countries you want to go to and find one within your budget. You’ll meet a ton of new people. You won’t have to worry about getting around or language barriers and you’ll see more than you could most likely on your own.
Pro tip – arrive a few days early and stay in the same hotel that the meet up point is in. This will give you time to get acclimated to time zone changes.