A lot of this depends on what you like or want. I’ve been a lot of places, and they all have merit. If you haven’t traveled abroad before, I think Barcelona and the surrounding areas are a great trip for first-timers to get their feet wet. I think it’s a really cool city; it’s easy to navigate and you can get by pretty easily if you don’t speak the language. Same goes for Paris, except maybe the “easy to navigate” part.
If you like more outdoorsy type things, you can’t beat Scotland (which also has cool cities). The weather kind of sucks, though. The Highlands and the Isle of Skye are awesome and full of castles.
Sicily is also really cool, especially if you love historical stuff and cool old architecture from all of the different empires that have ruled the island over the years.
I haven’t been to any of the places you listed. I was right on the border of Argentina when I was in southern Chile, but never crossed over. Southern Chile is also very cool if you like the outdoors stuff.
Honestly, I’d prefer if the OP was upfront about getting laid.
Yes, the ideal scenario would be where the OP goes to a touristy-yet-safe place full of natural and historical wonders and then hooks up with the local-yet-slightly-exotic hot girl who out of millions of tourists that frequent her country each year chooses him for no strings attached Tinder banging.
However, that’s probably not gonna happen so the OP should be more specific.