I downloaded the 1.2.4 test patch, and I loaded the game. I suck at computer stuff, but does it automatically work or do I have to do something? 
Firstly, you need some sort of Insurgence core, think of it as a ābaseā with the essentials. The latest is the 1.2.3 core, downloadable on this website at the top. This automatically works and you can play the game.
The 1.2.4 patch is, well, a patch. Itās not a base, so it doesnāt have any of the essentials, rather it is used to replace(or āpatchā) certain 1.2.3 files.
If you have the 1.2.4 patch then I assume you have access to the Insurgence discord. I believe they have a FAQ portion that tells you how to apply the 1.2.4 patch(Iām not sure however, I havenāt been on in ages).
If you arenāt comfortable with patching and stuff, Iād strongly suggest just getting the 1.2.3 core at the top, that automatically works when downloaded and unzipped.