Trackpad
if I install a bluetooth track pad will that deactivate the keyboard trackpad
MacBook Air 13″, macOS 13.3
It shouldn't. You can have multiple "human input" devices like external keyboards or mice. I've never seen an external mouse connected that would disable the trackpad. Sometimes I'd even use the trackpad to do a quieter tap rather than a more audible mouse click.
It can get a little bit odd when two pointing devices are used at the same time. As far as I can tell, with the internal trackpad, an external device will generally win out.