How do I block the sun coming through a glass wall?

Wow! That must be awesome! Another concern would also be the pantry area, hot sun is not good for some of those items. This might need to be a custom job. How wide are the glass bock windows? My initial thought was to install bamboo roller shades, but that may not be feasible. You might consider setting up appointments with drapery or window dressing shops to see what they suggest.

As to the openings on the second and third floors, they make pre fab child and pet gates that you can install. Can you share photos of those openings?

Hang a thermal line curtain on a tension rod to help with the heat.

You could add lattice or banisters to raise the height or install glass block there as well.

Hang sheers on curtain rods that can be moved to the side to allow more light when needed. Roller shades with semi transparent vinyl. Might need custom work done. Low railings in the openings would make them safe for the kids.

Possibly use vinyl removable contact paper on each square. Shaded or clear with design. Time consuming but less expensive. As to protecting the bottom of each. Thinking white (or matching color/theme) railing/fencing. Put two (or whatever is needed) across the windows both floors. Can be easily attached and removed when needed. Good luck! Would love to see your finished project! 👍

I have a 2 story wall of windows that lets in too much sun and HEAT! I use solar shades outside spring through fall. I had them installed with pulleys so I can put them up and down myself every season.

It may be a bit time consuming, but I highly recommend Gila window film. I used it in an old house that had 9 floor-to-ceiling windows on the west side of the family room. It would be easy to fry an egg on the back of the sofa, not the least of which the solar damage to flooring, furniture, artwork, etc.

I added Gila window film to the glass of all of the windows and we experienced an immediate change. The room became much, much cooler and we didn't have to worry about the sun damaging anything.

Since then, I've used it on the windows of our current home and have experienced the same positive results.

When the sun is at its most intense, I can put my hands near the glass of our windows and feel NOTHING.

I bought our Gila film at Lowes and it's not mirrored or such, it comes with nearly invisible capabilities.