Sounds like an amazing trip,
@PortageTerrier! I won't repeat some of the recommendations here but you'll find that there is way more to do in DC than time to do things. Walk around The National Mall and check out the WWII, Vietnam, and Korean War Memorials and check out the Washington Monument as well as the Jefferson and Lincoln Memorials. Renting paddle boats and riding around the China Basin is a nice tourist-y thing to do as well (weather permitting).
Looks like there is a 10:15a practice before the Jets game (
prax schedule here) and they're open to the public but I would also follow Samantha Pell and Tarik El-Bashir on Twitter (if you're a Twitter guy) as they're the Caps' beat writers and always post relevant info about practice schedules, etc.
With a 14-year-old, you may also want to check out the
International Spy Museum. It's not free like the Smithsonians but it's a really neat experience. It's about 2 miles from where you're staying and probably about 1.2-1.5 miles from Capital One Arena. If you're doing the Smithsonians, I rank them: 1. Natural History, 2. American History, 3. Air & Space. The Air & Space Museum is under construction right now and while still open, not as cool. If you or your kid are 'air & space nuts' and you have time, take a trip out to the
Udvar-Hazy Center. It's a bit of a trek from downtown DC but it's terrific.
Anyway, have fun; it sounds like this will be a trip you and your son will remember forever (and hopefully Ovi gets 700 while you're here if he hasn't done so already)!
Mod note: will move this to the Out-of-towners thread in a few days.