Legal regulations for eBikes

Hey everyone!

I've been seriously considering getting a cargo eBike, maybe something like a Tern GSD or a RadWagon, to replace some car trips for groceries and school runs. I'm getting a bit hung up on the legal side of things though, especially with the extra weight and potential for carrying kids. Does anyone have experience navigating the specific regulations for cargo eBikes, particularly regarding motor wattage limits or speed classes, in different states or even just generally? I'm curious if they're treated differently than a standard eMTB or commuter eBike.