A key has several cuts, one for each pin. Most of the time there are 6 different depths possible for each cut and every cut allows the pins to lift to the correct position.
There are usually between 5 and 7 pins, unless it's a disc lock, which takes extra skill.
You number the pins, 12345 from the head, then number the depth of the cuts, so maybe go 13542, 1=1 2=3 3=5 4=5, you have the key mapped.
The best picks are made, not bought. Street sweeper bristles are excellent and often lay in the gutter, they're spring steel and are easily shaped.
Piano wire or guitar strings work too, especially on safes and disc locks.
I don't have a video link sorry, but you should look at a technique called impressioning. It will give you a key, not simply unlock the lock. Get yourself a copy of Greg Miller's book if you can find it.
You also have bilocks, medeco locks, dimple locks, disc locks, lever locks, warded locks, Brink's function locks,...
A simple pin and tumbler can be jiggled open most of the time. Just keep practising and use whatever tool works best for you.