Look up in the top right corner of your screen for the magnifying glass. Click that and type in "Blockland". A folder called Blockland v16 should show up. That is the folder.
This would be the best way.
The Blockland disk image tells you to put your Blockland folder in applications, but you can put it were ever (as long is it can write there) you want and it will run just fine.
Just like you can install your blockland where ever you want it on PC.