Lock Picking Can be used to get past locked doors, but not every door can be picked. The only thing you will need to start lock picking are some bobby pins, you can buy them at the gas station or they can be found as random loot.
When you're lockpicking, Aiming to the left & right with your mouse will move the pin around, think of the lock as a clock, aim at every second hour, from 9 to 11 to 1 to 3, which is where you should place the pin to pick the lock, it's random each time. Once the pin is in one of the possible spots, hold F for a brief moment to see how far the pin turns without getting stuck. If it moves a bit and gets stuck (shaking noise) that means it's not in the right spot. Depending on how much it turned, move the pin either closer to that hour, or to a different hour if it doesn't move enough.
(Big thanks to V7X#5132 on the DDS discord, they helped me a ton and I basically copy and pasted their message with permission of course)