I can never rope people into traveling with me, but that's probably due to my autistic-level special interest in/obsession with the world that used to be behind the Iron Curtain. Most French people don't want to do anything other than sit on their asses on our filthy Mediterranean beaches. (Seriously, I once went from Frejus to Tunisia and the Tunisian beaches were cleaner and more free of harassing dudes trying to sell tat.)
For a first trip outside the U.S., depending on your general comfort level with the unknown, you might want to start with a country where English is widely spoken and the infrastructure is decent. I assume you've probably either already visited or aren't interested in Canada/Mexico. If I were going to stretch my budget I think I'd find the flight deals first and then choose the destination (do you want beach, city break, wilderness, agritourism, something else?). If you want to check out Western Europe, which is a good first international destination IMO, I would suggest skipping the big capital cities that will suck away all your money in an instant and are no longer an authentic representation of their native cultures--pick the "second" cities or regional capitals instead. For example, I wouldn't recommend Paris to my worst enemy. But La Rochelle is a beautiful seaside town with far fewer social problems, lots of fun festivals and events going on all summer long, and mostly domestic tourists--you're not going to be chased down by waiters from shitty "restaurants" with menus in five languages there, not for the most part. And the islands near there, especially Noirmoutier, can be idyllic. In the southwest, Bayonne is a good alternative to Biarritz. The Auvergne in the massif central is gorgeous and affordable. There's a whole hidden "redneck" France more in the interior with forest night markets, toro piscine, DIY river locks, old Roman roads converted into bike trails through endless vineyards and sunflower fields, and other weird things to do. You get the picture. So I'd choose my affordable flight and then find someone from whichever country you choose who can steer you towards the authentic, always lower-cost, experiences.