i apologize in advance if the tone of this sounds harsh, i am actually very amused as i write this because your situation happens all the time, i.e. you're not the first to notice the difference between the 'noobs and the 'oldsters at work ;-)
the first flaw: "old school" vs "new school" - assuming your seniors are "old school" and therefore inferior is called prejudice, and is not a very good way to start your career.
chances are, the "old schoolers" can and will code circles around you, especially in their domain. Since your new job depends on learning their domain perhaps you should learn and befriend them first and try to teach them later, after you have earned their respect...
...and definitely keep your "new school vs old school" prejudices in check; if your "aging" coworkers (as if you are immune from aging!) perceive you to be a know-it-all "punk", no one will want to help you. It really doesn't matter even if you actually do know it all, no one likes a punk. ;-)
so pretend to be humble for the first few months, listen carefully, and be ready to learn more in your first year of real work than you ever learned in college!
as for your specific issues so far, here's another way to look at it:
- waterfall works fine with experienced developers and a target that isn't moving too fast
- what you call "collaboration" i might call "interrupting my concentration"; code tends to be written most efficiently by individual programmers working alone and uninterrupted; continual multi-tasking is inefficient
- working during normal business hours is what normal employees do; get used to it. There is an advantage to being in the office when your customer is also in the office. Of course there are also disadvantages. The balance between the two is called "time management" ;-)
as a corporate noob, you are expected to ask a lot of questions. Just don't jump up and interrupt the seniors every ten seconds like a toddler, save up a hand full of questions and interrupt them only a few times per day.
the good news is, the fact that you asked this question means that you care, and as long as your seniors can sense this about you they will care about you, too.