You certainly can install software via command line if you want, but that is not the recommended method for us newbies.
Mint Install is fool proof as a GUI tool and it is built specifically for Mint. Synaptics is also very good and contains many more software programs(packages), but not all have been tested and verified for Mint. I have experienced no problems with installation using either method. What are you using as a platform. PC? Laptop? Navigate through the menu and poke around. You won't break anything. Then if you find you need to do something and can't find an application, ask. Just use Mint update first, so you have the latest SW and fixes.