HOWEVER i would recommend definitely bring a water bottle and be prepared to walk more than a few blocks away from the mall if you want to get any food that isn't from a vendor cart
there should be porta potties if the rally has done the whole permit thing but if there's not, you might be able to use the ones in the museums, idk what their policy is for dogs though
and if your phone dies and you can't use google maps, just remember, alphabet streets are horizontal (east-west), number streets are vertical (north-south), and state streets are diagonal (virginia, etc)
so as long as you remember the intersection of places you're trying to get, once you figure out what cross street you're at, you can find you way there