Hey @Holly and welcome to the forums!
@QuriousPatriot’s instructions are correct.
However, I see you are using Mint 19. Is it the 32-bit version? If yes, then Brave will not work, as it’s only for a 64-bit system.
The way you can find if you have a 32-bit system is to open up a terminal and execute the command:
uname -a
Press Enter at the end of the line. If - in the results - you see X86, then you have a 32-bit system. If you see an X86_64, then you have a 64-bit system.
As a “fast” route, you can utilize a script we have up, to automate all the commands for Brave installation on an Ubuntu/Mint/Zorin/Debian distro: