The message already tells you:
A Question2Answer database query failed when generating this page. A full description of the failure is available in the web server's error log file.
You can't access the web server, so you can't access the file. (What is a web server?)
I will try to explain this error. All the posts in PokeBase exist in a database, which is like a collection of tables of data. PokeBase uses software, configured on a web server, that interacts with this database. When you load a PokeBase webpage, the software sends a request to the database for the data it needs (a "query") so it can assemble the webpage for you. The error message is saying that the query failed, which could happen for any number of reasons (which is why there's an error log so Pokemaster can find out).
In this case, I do know what the problem is (because it's happened countless times before). There is a limit of 8000 characters for your "about me", and when you send an update that goes over the limit, an error occurs. To stop getting the error, you need to shorten your "about me".