every time I try to use the brush tool when using select and mask I get a message saying "could not complete your request because of program/disk error"
I am very new to using Photoshop please help
As you are getting "Could not complete your request because of program/disk error", could you please let us know which version of Photoshop are you using and on which Operating system?
Also, please refer to this article and let us know if it helps: Troubleshoot issues with networks, removable media in Photoshop
I'm using the newest version on Windows 10.
Are you working on a big file? Photoshop needs at least the size of your file as temporary file. I am working with a Macintosh, but I think on a PC you can use a external disc as space for Photoshop to use for its temporary files. In the preferences you can choose the external disc, you want Photoshop to use: