I assume you installed the Turnkey LAMP appliance rather than one of their other products?
Well, I guess you start at the Web based admin pages
Turnkey Linux is derived from Ubuntu so you can probably also follow Ubuntu documentation if you are comfortable with the command line and have read an overview of Apache concepts.
If you don't have DNS configured to associate "exmple.com" with the IP-address of your server, you should start with that. Is this for LAN use (i.e. personal or "Intranet") or external use (i.e. an Internet facing server behind a firewall/router)?
Have you read the documentation for Apache and for ftpd? which parts are you having problems with?
Are you editing configuration files directly or are you using a GUI tool? If so which one?