It is a good move to always install software from the repository if possible (from software manager or synaptic package manager)
This is because you are guaranteed security, and you are guaranteed updates which are also secure.
I will only install from an outside source when absolutely necessary. A couple of disaster installs from the internet which resulted in total reinstalls of the entire OS very early in my Linux experience, convinced me of two things...1. Install from the repositories, and have Timeshift operating.
I recently attempted to update to 19.1...the update was as easy as pie.....but the resulting os was not what i expected and left a lot to be desired.
I put the usb in with LM 18.3 on it and it took Timeshift 25 minutes to reinstall the whole thing (back to 18.3)....perfectly.
Installing from software manager is simple.....Synaptic package manager is a little more complicated, but very powerful.
This also takes away the urgency that was present in windows to always be updated to the latest...mainly for security reasons. With Linux that pressure does not exist. In update preferences I do not tick the box that says "Hide the update manager after applying updates".....this allows the update manager icon to always be present in the system tray (down in the clocks general area).....it usually sits there with a tick in a shield.....it changes tom a blue dot when there are updates available.
if you haven't done so already take a look through the preferences section of the update manager....any you are not sure of, or do not understand, just yell out.