The bike shop put on my Shimano Click'R pedals. These are by far the easiest pedals on the planet to clip in and out of. Then I put multi-directional SPD cleats on my bike shoes. Easy peasy. You unscrew two little screws on the soles of the shoes. A piece of sole pops off. You attach the cleats with the two screws.
Years ago I had this done as part of a bike fitting. Unfortunately, I can't see a fit guy right now because of this virus thing. So I basically trusted in luck.
There are a row of joints, the MTP (metatarsophalangeal) joints, that form the ball of the foot. I needed to know the line these joints make on my foot. Everybody's foot is different, but for most people, the MTP line won't go straight across the foot. It will angle a bit or a lot. Once I knew the points on each side of my foot, I put my foot in my bike shoe and marked those two points on the sides of the soles.
The point nearest the crank should be slightly in front of the pedal's axle. The outside point should be slightly behind the pedal's axle.
I was going to do the first short ride with Al. I thought I'd just trust luck. I was a bit short of time, so put the cleats in the middle position on my shoes. (You know, the Goldilocks setting, not all the way forward, not all the way back.) I knew they would need adjustment, but the thing can only move a part of an inch. How big a deal can it be? I was just going to practice clipping in and out and stuff like that on my first ride. I hadn't done this stuff in a couple years, and I was a bit anxious.
It turns out, it can be a big deal. In 35 short miles, my left knee hurt, my right ankle hurt (a lot), and my right hip hurt. I limped when I finally got off the bike.
I adjusted the cleat positions to make the MTP joint lines align properly with the pedal axles. The next day Al and I took another short 35-mile ride. Success! No pain in the knee, hip, or ankle.
Lucky me.