Fidonet membership is not to be taken lightly. Every member has certain responsibilities, set forth in Fidonet Policy 4. There is really only one rule -- that you run an FTS-0001 compliant mailer during ZoneMailHour (ZMH) daily.
Fidonet is open to any and all comers who are able to meet the ZMH technical requirement, but is not something you join on the spur of the moment without understanding your responsibilities. You will really need to have at least a basic understanding of how Fidonet and your FTS-0001 compliant software work.
The best way to gain this knowledge is to both participate as a user on an existing Fido-BBS, and to set up your own not-yet-linked-to-Fidonet BBS. Once you have a basic understanding of what Fidonet provides and how your software does this, you are ready to proceed with joining as an official member. Don't let this scare you -- virtually nobody knows what's going on when they first join. There will be plenty of time for questions and usually tons of help available to you later. Waiting until you have a little bit of understanding will simply ease the process for both yourself and your Net Coordinator. Remember that your NC is just a hobbyist too, has plenty of work to do already, and often has several other newcomers like yourself needing help at any given time.