If your PC is not powerful enough then you will have to use the standalone Quest version indeed. And as you mentioned, the application need to be "sideloaded" on your device, because Oculus won't allow us to publish an adult game on their store.
The procedure is pretty straightforward and very well documented so you should not have any trouble. You can start by reading the instructions at the end of this post on our Patreon page, and you can also look for sideloading tutorial on Youtube if you prefer. Once your Quest is correctly set up, sideloading a game like ComeCloser is only a matter of copying a file into a folder.