Welcome to the forum.

Once you get the CNC itch there's no going back. Post up some ideas, have a look around the build logs, and let us know what you want the machine to do.

On the programming side you can write gcode manually to control the machine but these days there are very good CAD and CAM packages which will do that for you. Then there are machine controllers which takes the gcode generated by the CAM software and move your machine around. Mach3 and LinuxCNC are popular as somewhere to start.

Good luck with it and be prepared to develop the design based on the hard won experiences of the forum members.

There is usually someone who has been there and done that for just about anything DIY CNC related