Upgrading from ubuntu 18.04

I am getting messages that there is an upgrade available for ubuntu 18.04. I tried installing ubuntu 20.04 and it was a disaster. I purchased dvds from 3 different sources that claimed to be final versions of 20.04 and all 3 were appeared to be incomplete beta versions with so much missing they were worthless. I had no problems from 10.04 to 18.04 using dvds I purchased. I got so tired of hunting here and the web for missing software i gave up and went back to 18.04. What will happen if i click on the upgrade in 18.04 will I lose any programs or saved items in 18.04?