I'm local and go to the parks solo all the time. I absolutely love being able to make up my own schedule, being able to change things on a whim, taking the time to explore little things I might otherwise feel bad about if I was holding other people up, etc.
The only recurring thing that I don't care for is dealing with quick service dining when it's really busy - trying to find an open seat while balancing a loaded tray of food, not feeling comfortable leaving my things at my table (once I've found one) to get up and get a drink refill or grab extra napkins or whatever. I usually just try to eat at off times (2pm instead of noon for lunch, etc.) and then it's a lot easier to deal with because it's less crowded. I don't usually do sit-down restaurants, just because that's not really my thing, but that might make things easier, too.
I do always make sure to bring headphones or earbuds along so that when the family in line next to me starts arguing or having an annoying conversation, I can just listen to music or podcasts on my phone and drown them out. I also bring external chargers for my phone so that I can play games during all the line waits without worrying about my battery dying.