TimeShift has been included in Mint since 18.3 and you are recommended to use it for keeping your system safe. As it is included you do not need anything further to install it. Since the start of the 19 series it is the in the Welcome Screen under first steps. It is the first item there called System Snapshots with a large red T.
It is a simple tool to use and should be the first thing you do. Once this is set up you really do not have to do bother with it again unless anything is wrong.
Although the is a different item to the thread here I have answered it this time. There is another thread about it on the community pages -