Hey there mate!
You are almost there! I assume that this said folder containing Beancash files is located in your download folder. If it is the case, go to that directory with your terminal.
NB: In terminal, when you are typing something, pressing tab once will fill the word until there is a difference and pressing tab twice will show you the different possibilities.
That said you can navigate to your beancash folder by using cd;
cd Dow (press tab once here and it should now be written: cd Downloads/)
So continuing forward before pressing enter;
cd Downloads/Bean *press tab once* and then enter if it is the actual unzipped folder of Beancash.
NB: Also you can type ls which is a command that will list the content of the folder you are in.
At this point all you need to do is run this command to run the wallet:
By doing this with the terminal, you will see if there is a dependancy missing on the terminal. You can add those deps by using;
sudo apt-get install filename
IE error missing libQtGui4 bleh bleh bleh
Then you would type;
sudo apt-get install libqtgui4 *press tab twice to see the options here* and select the appropriate library (lib)
Finally, once you have it started with the terminal (no more missing deps) you will be able to double click the Beancash-qt and run it with your mouse if you want.
This will put the beancash blockchain and wallet inside the .Beancash folder which is hidden in your username folder (ie /home/USERNAME/.Beancash)
Since Mint is also debian based like Ubuntu (if I remember correctly) you can probably press ctrl+h to unlock hidden folders/files when in your file manager.
Hope this helps mate!