I have been playing violin for three years, so I guess I will try to help you
First, it doesn't have anything to do with positions: instead, it's finger patterns. The first note you learn on a violin is normally the low E. To play this E, you would go to your D string and place your finger ABOUT an inch away from the end of the fingerboard. Your finger is playing a High 1. If you were to play an E Flat, you would place your finger about a half an inch down from where you played your last note. This is now Low 1 and you have just played a half step.
A Low 2 is a half step up from your High 1, so place your second finger (middle) right by your High 1 and you should be playing an F. To play High 2, you would move that finger up a half step. A Low 3 is your third finger placed right by your second finger. High 3 would be another half step up. A Low 4 is the same as your High 3, just played with your pinkie finger. A High 4 would be a half step above that.
I know it sounds confusing, but just try it and if it doesn't help, YouTube is always a good resource
. Good luck.