My advice is fairly simple, but based on sort of a catch-22. Inferring from your post, I'll venture that you lack the experience (or maybe just the confidence) to tackle a tricky lace pattern, or analyze the implications.

So my advice is to build a straight 36h wheel. Since you're not heavy, you can reduce the amount of spoke by using lighter spokes rather than fewer spokes. You'll end up with an easier to build, lighter wheel which will serve you better over the long haul.

One advantage of 36h is that there's very short spans between spokes at the rim. That allows for lighter rims, and provides form precise aligning, and correcting of variations in the rim. If you drop to 28h, the spans increase, so you'll need a stiffer (heavier) rim, and will some degree of precise control of rim alignment.

Or if you really want 28H, consider the old KISS approach and spring for a 28h hub.