When you first open OBS Studio, you should be prompted to go through the auto-configuration process. If the Auto-Configuration Wizard tool doesn’t automatically pop up, you can find it in the Tools menu at the top of your screen. Run this tool to let OBS automatically check your system’s requirements and attempt to find the settings appropriate for your computer. This should include the settings for your recording, resolution, encoder, bitrate, and other settings.
Once you’ve run the auto-config tool, check that OBS is set up for your preferred audio device. You can do this by clicking Settings > Audio. Then verify that it has the right audio device selected or change it if you’re using another device.
Next, you’ll need to add your video source(s). Find the Sources box at the bottom of the screen and click +. This will give you several options, including Game Capture, Window, or Video Capture Device (for capturing webcam video). Select the appropriate video source(s), and you’ll be set to start recording.