This isn't a Bedrock Dedicated Server issue. (from what I heard however, you have to login as an anonymous user or have NSO on both users in order to have local multiplayer working)
If you use ipconfig, you should be able to find your local IP (connect to only devices on the same network). To find your public IP (connect from devices not on your network), you first need to port forward your game, then use any number of online tools to find your public IP (searching "what is my ip" on Google should help).
You have to install the Visual Studio 2015 C++ Redistributable. (likely the x64 version)
It was likely chosen to be better than TCP for them.
Same as BDS-53 (earlier original issue), marked as one that's invalid/resolved. What's going on is that the Bedrock Server isn't built for ARM processors, aka the Raspberry Pi won't run on it.
From what I can probably guess, the server doesn't actually create files if they're not found. To disable the error opening ops.json and whitelist.json just try creating the file manually (may be a bad solution though), just make sure it's a valid JSON file by adding {} to it. As for the log file, I have no idea what the filename for it is.
A thing to note is that both Minecraft: Java and its server counterpart both run on the Pi (albeit slowly). There's also a version of Minecraft: Pocket that is rebuilt for the Pi, showing that it has been done before. A lot of cheaper single-board computers (ideal for setting up a server for maybe a group of 5 people) use ARM, meaning hosting an always-on server would be quite a bit for some people, especially younger people.
This is likely due to the loopback policies. There will be a HTML file on the same directory as the executable that explains how to fix it.