For those trying out Linux, here are some quick instructions on how to quickly set up Linux Mint (or any other Ubuntu-based distribution) to be secure and easy to use. The screenshots are from a fresh install of Linux Mint 20.1 Cinnamon, but other recent versions are nearly identical.
When you first start up Linux Mint, you will be greeted with the welcome screen.
Clicking on the First Steps option provides shortcuts to many useful tools. The first two, Desktop Colors and Panel Layout just change the appearance.
System Snapshots is a recovery program called Timeshift for the operating system; if an update or change you make ever breaks it the snapshot recovers the previous state, however it does not back up your personal files. When first launched, there are several settings tabs; selecting the default settings works well for almost all cases.
Driver Manager only applies for computers with a dedicated graphics card. The default xserver-xorg-video-noveau is open-source but is not optimized, so switching to the one with the (recommended) label usually is best. Note that the computer will need to be rebooted after changing the driver.
Update Manager installs available updates. It is recommended to update frequently, because Linux systems use frequent security updates to patch bugs to avoid requiring antivirus software. I typically update once per week. Note that the computer should be rebooted after updates.
System Settings is self-explanatory.
Software Manager is the preferred way to install new programs and applications.
The Firewall needs to be enabled, but it is very simple.
Open the Firewall launcher, click on the Status slider once and it will light up and the firewall is active. The default settings work fine. The Firewall step is complete