I built a CNC machine as a lock down project during Covid. It had a cutting area of 800mmx600mm, it was fun to build and the aim was to design a machine to cut foam for tool drawers, it didn't really do the job I thought it would do, and whilst it was a great learning experience, I have the machine away to the local school to make better use of it. As I was doing anything with bass guitars then, building a bass from wood with a CNC machine wasn't even a thought.
If I was going to do anything with a CNC machine, I would go for something decent such as the X-Carve that @Richard R has commented on. I did just check it at https://www.inventables.com/products/x-carve-1 and it appears that the nice entry level kits have been discontinued and they are moving to the X-Carve Pro which are bigger and more money. However there are other kits or systems out there to replace the entry level stuff. I wouldn;t suggest making your own though as I did
Rob