I lived abroad for a semester in high school (my dad was teaching college classes overseas and my school okayed me to withdraw for that amount of time).
We lived in Regensburg, Germany and it was absolutely gorgeous! I wouldn't trade that experience for anything in the world. We did a lot of traveling (10 countries) - my favorites were England (for the culture), Switzerland (for the scenery), and Austria (for both). Regensburg itself was the perfect "home base" for us - I have great fondness for that city.
Traveling was very easy, from our perspective. We got train tickets and used them every weekend to go to a new country. Transportation was easy too - so many of those cities have so much history that they are set up for walking because they were built long before cars were thought of. We walked pretty much everywhere and when we couldn't, we would occasionally take a cab.
My least favorite: Italy. Specifically Florence (Rome was okay and Venice was pretty). Florence was loud (motorbikes), dirty, and we encountered the most rude people there, so it was not the best experience. It's not a cultural thing - Venice we met some very nice people, so it's all in who you run into. Although England had more people who seemed to look down on Americans (we expected it from France lol! Goes to show, never listen to stereotypes). In spite of that, we did love England - London specifically because of all the history and nightlife.
I also wouldn't mind seeing Paris again. That was the only city we took two separate trips to - intentionally (we passed through Munich, a lot, to swap trains). We went back because we didn't feel like we'd seen everything - that's when my parents took me to
Disneyland Paris
.
The language barrier was not an issue - I was 15, almost 16, and I picked up German (the basics) quickly, but most people overseas know English - it's taught in schools from a very young age, so we muddled along just fine. I knew enough German to get by and they could fill in the blanks in English. Restaurants, we pointed at what we wanted on the menu - all very easy (that was our most stressful thing when making the decision as a family - could we overcome the language barrier for a semester, but it really wasn't a big deal).
Would I do it again? Yes, absolutely, if all the chips fell into place. This time I would revisit my favorite cities (London, Salzburg, Regensburg) and I would work knew countries in that I didn't get to before and really want to see (Greece, Ireland, Scotland).
Oddly enough, I'm scared to fly now - I was fine at that age, we flew to Europe and Poland and the Bahamas and other places in the U.S. and I never even noticed I'm in the air, but ever since I had kids, I'm terrified to fly. I told my husband that when we have grown kids, I'll take a class to get over the fear and we can go to Scotland (the only place overseas he wants to go), so it's a goal
.
Good luck on your decision!