Thanks for all your help. I realized that I can't read. I made a typo in the RAM allocation field for the docker container and it wouldn't boot as a result. I fixed that and did as Darqfallen and Marshalleq suggested, and it's working great!
In the setup for the lancache docker it specifically says not to change ports 53, 80, or 443. I think both it and Pi-Hole need to listen on those ports because they are filtering web traffic, right? I'm certainly not a networking expert, it just seems logical to me that they both do the same thing to the extent that they process DNS traffic on those ports?
Does anyone have any guidance for setting this up alongside the Pi-Hole docker? I can't even get the lancache docker to start when Pi-Hole is started. I think it has something to do with the port assignments. They both want to use 53, 80, and 443.