You could try the Caribbean as your first solo trip but be careful, you might wind up moving here as I did!

Australia! I'm from the US and have been 4 times in the past 5 years. I'm absolutely in love with the places. It's clean, safe, and the most friendly place on Earth. Absolutely so much to do that I found myself amazed this past July with how much I hadn't done despite my many travels there. You really need a minimum of 2-3 weeks just to get a feel for the place as it's almost as big as the US but it's the best place in the world. My first trip invovled starting in Cairns and traveling to Sydney. Since then I"ve spent the majority of my time in Sydney because I do a houseswap, but there is also the Outback, Melbourne (gorgeous), and the west coast that I"m dying to do. If you like adventure and the outdoors then please do my dream trip to the Kimberley region north of Perth! Can't go wrong Down under!

Email me at [email protected] if you want more help.

Paris! lol alot of people speak English and the metro system is so easy to use and to get around. Eiffel Tower, the shopping, Notre Dame, Louvre, Musee d'Orsay. Ton of stuff to see and do.

Getting in on this a little late, but .... I started solo travel when I was 22 (half my lifetime ago) and have Australia, Hawaii, Mexico, Belize, Costa Rica, Germany and most of the western U.S. on my solo list. My advice: stay in youth hostels. Great place to stoke up on human contact, meet travel companions and find out where to go, what to do. Also, watch your stuff. Never had anything stolen, but I am very careful about my valuables.
I've been to other destinations with companions, but the solo trips are special. Costa Rica was fabulous especially since my Spanish is very rudimentary and I flew into San Jose with only my first night planned. In Belize City, I stood in the airport for a while still trying to figure out if I should head inland first and then out to the islands, or vise versa. While in Tasmania I circled the island in a manual shift rental car with everything except the shift pattern reversed. (If the windshield wipers started up, it meant I was going to turn!) And what fun turning the old army jeep up the very steep, one-lane sand trail on Fraiser Island with 3 Irish, 1 English and 1 Canadian passenger -- prayer does work, I didn't encounter another vehicle coming the other way!
Anyway, it's a big world out there and going solo lets you set your own pace. I got married 2 years ago and my husband is getting the travel itch, tho he likes to relax on vacation. Relax?!! It is wonderful to have someone to travel with (no longer have to drag the backpack into the ladies room), but in the meantime keep going!