Don’t do what I did for these parade photos.
What you want to do is arrive about an hour to an hour and a half before the parade, if not earlier. This is for two reasons. First, you need parking time. Plan on lots of people planning to see the parade and that means parking might take time to figure out. Second, you want to survey the area. This will allow you to find the best locations to move to and also get a general idea about which areas along the route will likely be more crowded.
What I did was show up thirty minutes before the parade, offset the time sink by parking further away for $20 and booking it to the parade route. Fortunately, I am familiar with downtown Annapolis and the parade, so I had a few ideas of where to be. Not everything was the same, but I knew enough to adjust. If I wasn’t familiar with the area and the parade, then I would have been sunk.
I used my 70-200mm lens for this. It worked well for the areas I was operating in. Straight on photos didn’t work out but I was able to get a spot on the edge and catch them as they paraded towards me. I stood and kneeled to line up shots as needed depending on the crowd.