The things that disappoint with a first scope-
- Deep space objects, galaxies and nebulae are shades of gray and not in color.
- Many targets appear very small.
- Difficult to find a target, particularly if you are observing from a city or large suburb.
- Planets are not sharp when you use the high power (shorter focal length) eyepiece that you bought.
Everyone had advice often good advice, but sometimes not and often advice based on adult experience and without considering where you and your son will use the scope.
I think you should assume that your son will either get tired of the scope sooner or later or want to move up to a better one (applies to dad also). Therefore it makes sense not to start too high on the quality features scale. The Celestron Powerseeker isn't going to be mistaken for top quality, but it will not be awful. The line includes both EQ and Alt-az mounts and some go to mounts. This f/5 refractor isn't go to but it will have nice field of view. The other thing about scopes and mounts in this range is that you can often find them on CL for half of the retail price- almost a throw away scope.
Another option is the Celestron scope from Astronomers without Borders. Not by any stretch a perfect scope but a good one according to many people.
To get an idea of the relative size of objects in various scopes go here and try the visual field of view calculator. You can pick a scope from the list or customize one, same for the eyepiece.
Later you can worry questions like what kind of finder, red dot, Telrad or finder scope.
When I was young, a bit older than your son, I wanted a scope. I did the research and selected an EQ mounted Newtonian. My folks did the essential bit and I was the proud owner of a Montgomery Ward special. The eyepieces were crappy as was the mount and I didn't care. It was out to the yard to get the Orion Nebula, Jupiter and the moon. I guess that enthusiasm lasted a year more or less until I fully accepted that the complete kit in an urban backyard was not ever going to be a good astronomy or terrestrial setup. It was decades until my next scope, also crappy but I knew it was just a place to start.
Now for what it might be worth, today observing from a suburb I would only buy a go to mount unless the scope would also be used as a spotter.