OBS won't record sound from the mic on my headset

[CurryChiken]

I'm using OBS to record clips in games, but in the replays I always hear my laptop fan running which is super loud. How can I make it so that it only captures the desktop sound and the mic on my headset? Also, for some reason, I can't find my headset in the playback devices, so if there is a fix for that, I'll appreciate it a lot.