The "tutorials" where created based on older OBS versions.
Anyway, do not follow youtube tutorials because almost all of it is based on old OBS versions.
What you need to do is run the Auto-configuration Wizard (tools menu) and apply the settings it gives. Do not change any setting after this. Restart OBS. Yes, do restart OBS, it's very important to restart it.
Test is as is. If all goes well, you can try changing the recording quality preset for a better one and test again. If again all goes well, you're done.
Do not use advanced output unless you know exactly what you're doing.