You probably would have been fine with the 32 GB version. 64 GB is only if you need the extra storage for Apps (especially the Game Apps). The Remote Control takes some getting used to (I went in to settings and slowed it down a bit) but you should also be able to control your Apple TV with your iPhone and Watch. The Screen Savers are a nice touch.
Like the iPhone and iPad, you can group Apps into folders and also hide the built-in Apps that you never use. You can use the microphone button on the remote to have Siri open one of the Apps hidden in a Folder if you need it but can't remember what folder you hid it in. You can rearrange the Apps by a long-press and then slide them to where you want.
If you have a new enough Mac, you can use AirPlay to mirror your Mac's desktop to the Apple TV, or use it as a second 4K screen. Likewise, you can use AirPlay to mirror your iPad or iPhone to the Apple TV with varying results (some Apps don't like to share!)
The YouTube app is as bleh on the Apple TV as it is on most any other platform. No 4K YouTube video support, either. But the 4K using AppleTV+ will give your download speeds a workout.
If you have any HomeKit devices, they can now use the Apple TV as their Hub instead of an iPad. Since the AppleTV 4K is usually powered up or in Standby all the time, I've found it's more stable with my few items.
If you set up CEC and your Home Theater supports it, you should be able to navigate on your AppleTV by using the arrow keys on your Projector or AVR remote. The Apple TV can cause your TV and receiver to power up and switch to the appropriate input if CEC is working and supported. Also, if you're watching via the Apple TV and you want to shut everything off, press and hold the TV button (the one with the TV icon) and it brings up an option panel from the right. Press the touchpad and the Apple TV gos into standby and powers off the CEC-enabled connected equipment.
And if nothing else, you get a free year of AppleTV+ with your purchase. Just make sure the young ones aren't visiting if you sample "The Morning Show", "See", or "For All Mankind" The language is most un-Apple which I guess is necessary for any new streaming service nowadays.