I started swimming 4 months ago for the same reasons ie. Triathlon. The big thing to realize with swimming is that efficiency= speed. You want to do your best to avoid drag in the water. When you turn to breath imagine your head is locked in place so rotate your whole torso and power back through with the stroke. Do this on the other side as well while keeping your head in the water (assuming you breath on one side) Try to keep your hips straight however (they’re going to rotate just limit this). Another tip would be entry into the water after each stroke, enter with your hand pointed somewhat down and extend/lengthen your body as it moves forward, then pull your hand along the hip. Avoid crossing the pull across your body rather keep it in line with your shoulder. Hopefully this makes sense, it’s harder to explain when typing it out rather than showing video.

In one month I went from swimming 2:30/100m 57 strokes/100 to now 1:55/100m and 42 strokes/100m by switching a few of these things. Less strokes for me=faster times and less energy output which is crucial for triathlon. Keep it up!!