A perfect Position 1 is your life goal in weightlifting. Everything you do after you start pulling the bar off the floor(pos 3) is to get the bar to a perfectly balanced Position 1. So it makes sense to start learning how to lift from that most sacred(in weightlifting) position.
Stand Tall....bend your knees.....go! I say this over and over when teaching new lifters. They grab the bar with a snatch grip, I tell them to stand tall with their shoulders back, then they bend their knees, and finally they push with their whole foot and violently extend their knees to get the bar over their head. Where you catch it depends on overhead squat mobility. If you can get into a full overhead squat on day one, then I recommend catching in a full squat from day 1 so you don't get too comfy with power snatches. Things to watch out for when starting:
Thrusting Hips - One of the big reasons for starting with Pos 1 is to learn how to drive the bar straight up with your LEGS and not your hips. DO NOT start the motion from Pos 1 with your hips. The hips stay retreated(back) and the extension of the knees drives the bar up and determines the bar path. Often I tell people to push through their heels and quads from position 1 because the tendency is to roll forward onto the toes too early and throw the hips forward. Hip thrusting causes the bar to move too much laterally which is a waste of energy and causes more technique errors down the road.
Looping Arms - The arm action is often difficult for people to learn, so start out right with your elbows HIGH AND OUTSIDE. Afer the legs have finished driving, and you are on your toes, the arms should then take action and guide the bar into place above and slightly behind your head. The elbows should point toward the cieling and to your side. DO NOT pull back because that will cause you to pull the bar behind you, or if the weight is heavy enough, it will cause you to pull yourself forward. We want that bar to move vertically into place.
Again, keep in mind that you are using your legs to drive the bar up. Push the bar up vertically with your knees(quads really, but saying knees helps people not use their hips) and catch the bar overhead as low as you can comfortably go in an overhead squat.
Nothin' to it but to do it now. Stand Tall.....bend your knees....and GO!