To practise you might require a quieter pool/lane. Firstly, swim as close to the feet of your friends as possible – notice how this may change the technique at the front of your stroke, shortening your stroke at the front and reducing the glide.
Secondly, position yourself on the hips of your friend and tuck in as best you can. This can help you get used to flailing arms in the open-water swim mêlée. To demonstrate how effective drafting can be, swim a length starting on the hip of your friend and gradually accelerate past them until they’re positioned on your hip. You’ll notice how it gets harder to maintain the same pace as you swap positions.
Remember to keep practising these skills in the open water where possible to give yourself every opportunity to perform well come race day and actually enjoy the triathlon swim leg!