(a) Yes, now you're in the real world. Living in a dorm or in a student apartment complex often is more akin to living with an extended family.
(b) If the point is to make friends you can hang out with, I would think that getting a job that requires a lot of travel would hurt, rather than help. Sure, you'll meet a lot of people in passing, but do you stay together long enough to hang out and become friends? My niece took a job with a consulting firm. A group of them would be shipped off all over the world for 1 - 6 month stints. They would be housed together in a suite. Problem was they all worked such long hours they never had much time to hang out and visit the sites much. And the next assignment could involve a different group of people. And if you're shipped off later on solo assignments as you advance, you'll be even more isolated. So be careful there.
(c) A lot depends on your individual circumstances. I've worked at large companies with several thousand people at one site. There were usually after-hours (sometimes lunch hour) company sports teams (volleyball, softball, bocce, ...). We even had a company orchestra that would give concerts after hours or during lunch; and a foreign film club. If there isn't a suitable activity, consider starting one. One guy rounded up enough soccer players to form a company league.
(d) But my advice, which you probably won't like, is to become involved with activities that you can do solo after hours and weekends. I pursued cooking, baking, and ice skating, e.g. Swimming is another sport that doesn't require a partner. If there are public schools around you, check to see if they offer adult ed classes in languages, art, dance, and sports. Typically low cost; offerred evenings and weekends. You can take tennis lessons at a racquet club and sign up on a roster for partners to play with. At least your well-being won't depend on friends to hang out with, and who knows what interesting people you'll meet along the way? You just don't want to get sucked into the routine of work, come home, eat, watch TV, sleep.
(e) The lesson learned: When you consider a job offer, you also need to consider locale and your desired lifestyle. But it usually will end up being a compromise: you could end up with a great job with great pay in the middle of nowhere, or with a lesser job at lesser pay in the middle of a large city with lots of singles.
