spinning beach ball

For the past few months I’ve had the spinning Beachball of death on my MacBook Pro 2012 model. I need to make sure it’s working to take my nursing final test end of this month. I read someplace in the community that if I upgrade the memory it would resolve the spinning Beachball. I have the spinning Beachball appear every so often in between programs, searching, there’s a lot of lag time. I recently upgraded to Catalina two days ago and I have now lost access to Microsoft word excel PowerPoint and adobe after the upgrade.

how much will Apple Genius Bar charge me to get this fixed? any ideas? and can I replace the memory and get rid of the spinning Beachball?? Please help thanks