[X-Newbies] Questions re: Classic, Applications folder, firewall, faxing

[dfmanno at TOAST.NET]

I recently purchased a used iBook G4, and the vendor pre-loaded it with Tiger. I have no experience with OS X (my desktop runs 9.2.2), and 
so I have some questions:

1) I know that Tiger runs non-X apps under Classic. How do I tell if Classic is installed, and if it is not, how do I install it?

2) Is it OK to create subfolders in the Applications folder?

3) Is the firewall in Tiger good enough security, or should I be looking for a third-party firewall? How do I activate Tiger's firewall?

4) What's the easiest way to fax under Tiger?

Thanks for any help.

D.F. Manno