Hey OP, just a social golfer these days but did get down to 3 when i was 17yo, now 30yo, just hack it around off 7 for funsies with friends and social drinks but probably have a little usefull advice on getting the handicap down a bit.
Driving ranges, practice ranges are very overated imo op. You get in to a good rhythm on the range after 5 mins and hardly miss a shot, yet when on the golf course do you ever hit the same shot in sequence, never, unless you oob one and have to re load that is
One thing that has'nt been mentioned enough is working on your actual swing (plane- most important, grip, tempo and timing) and this is what i find the practice range is best for, not just plummeting down 100 balls in half an hour.
As for the short game, that is just a practice, practice and more practice spot until you have the feel and touch to be confident with all sorts of shots from 50m in and make sure you get on top of your wedge, sand wedge and lob wedge once you have mastered chipping with these clubs, your game and scores will be lowered dramatically, no chipping with 7,8,9 irons like a 70yo grandfather
All the best with it, will keep an eye on your progress.