If you don't intend to use Lightroom Cloud a lot and your workflow doesn't benefit from the cloud storage, get the cheaper option without that 1TB.
If you think 1TB cloud storage is a nice perk, there are quite a few ways to get it cheaper.
Possibly the best option (unless you already have it) is Microsoft 365. For $10/month you get perfectly separate 1TB for both you and your son (and for 3 other users). And they give you Office as a bonus.
I don't intend to start a license flame war, but just keep in mind that Adobe CC license is for 2 devices but just for 1 user.
So from a legal POV, you're letting another person use your license within a household (which is OK). But if you and your son don't live together, this is deep grey market at best.
From practical POV, Adobe will only allow one PC to use an Adobe account at a time.