How can I set up a wireless monitor for my computer?

TSasha Smith

I was wondering if I can set up a 4th monitor with a wireless monitor?  Do I need a smart tv for the wireless monitor.

Also I am thinking of upgrading my ram soon.  I think someone threw out my old computer for some unknown reason to me.  Do I need to get a backup computer to use while my current computer is being upgraded?  Wonder if I can donate the temporary computer to the day center I visit every so often?