When I was a teenager I got a 35 pound Ben Pearson Colt, about 34 at 28. Mom, bless her heart and may God give her a smile, went to the PX for new arrows for me. They were 1716s, cut to 28", which I am sure I never acheived. But I sure shot them well, and that is what I wold recommend.
Now, all of this is speculation, as the young man's draw length remains a mystery, as well as the bow's manufacture, and the pertinent details of its construction.
For simplicity's sake, I generally cut my arrows to 28", and see what spine works best. Tweaking can be done with heavier or lighter inserts or heads.
Killdeer