I unzipped the Forge mdk to it's own folder, i moved the build.gradle, gradlew.bat, gradlew, and the gradle folder into a new folder(within the folder that i unzipped all the contents to), as per instructions on the Forge documentation page. I then launched InteliJ, selected open, then selected the folder where I moved the build.gradle, and other gradle files. It doesn't build right away due to something odd going on with my JDK (sometimes IntelliJ wants to use an older JDK that is no longer installed on my system, I can't seem to figure out why), so I select the correct JDK manually, refresh the project, and the gradle builds automatically.