56 sounds like a reasonable sized frame for your height and leg length. I'm a tad taller with 2" longer legs and ride a 58----but could fit on some folks 56's.

Like many others I started back exactly like you---even a little heavier. I started with riding padded "underwear" under some sports shorts and platform pedals to begin with. However after about 10 years and a few thousand miles I've come to appreciate spandex, clipless pedals etc. Just a matter of what you prefer.

I'll be out your way in a few weeks doing Ride the Rockies. This will be my 4th year of riding in Colorado. What area do you live in? Just wondering if I've ridden through it doing RtR or Bicycle Tour of Colorado. Looks like this year we will not be heading towards the northern part of the state. I really enjoy riding in Colorado.