How to develop skills as a beginner mountain biker

[Irulan]

Part of it is just learning to trust the fatter tires and lower psi, and most of it will probably just take time, but is there anything else y'all know of to build skills? Any really helpful articles or youtube videos or general tips? I was having trouble with such basic tasks like slow tight turns - but of course it was my first time out there.

There is so much more than just trusting the tires. It is whole different skill set, more related to dirt biking (motocross style) than road bicycling.

For slow tight corners, you must be off your saddle in a ready position, and understand how to move laterally with your body and steer the bike. Lower your saddle for starters.

Taking clinics and using flat pedals are the two biggest confidence boosters. Mountain biking is the opposite of road biking in that you move around with the bike, a lot. Your body becomes part of the suspension. Most road bikers are very stiff, and afraid to get off the saddle and move around. Your most stable positions is OFF the saddle, feet level ( 3 & 9). if you are using clipless pedals, I highly recommend ditching them for some flat pedals while learning. Once you have solid skills, then you can decide whether you want to be clipped in or not.
Here are some good videos. Pay attention to body position and movement.

basic body position
https://youtu.be/52x5Z9meapQ

Don't let the "Freeride" or hucking scare you... the fundamentalst are exactly the same whether you are beginner or pro. This is an excellent video on all the fundamental skills.
https://youtu.be/F9vakhSvgt8