Honestly? Just keep training and you'll slowly get stronger as you go along. Some technique tips would be to make sure you keep the bar really tightly secured against your grip and your traps (don't use the neck foam thing, it fucks up your stabilizer muscle activation and makes you hunch which may lead to upper spine problems, just seriously look up a video on how to set up a barbell squat), find a comfortable foot position where you can squat down to where your butt can touch the back of your ankles and go light at first to get your technique dialed in, feel that deep stretch in your quads, go all the way down to the bottom and find a weight that challenges you to 10 or 12 reps and just keep training. That's it, there's no secret cue, it's just consistency and repetition.