You know the answer.

If the cops are impounding illegal electric dirt bikes, then if you buy an illegal electric dirt bike, it will be impounded.

You will have to pay to get it out of the impound yard, which is hella expensive. But once you get it back, you can't ride it. And you can't sell it, because no one else can ride it either. So it sits in your garage and rusts.

And you won't just have impound fees. You'll get a ticket(s) that you'll have to pay. And assuming that you are able to get a license when you turn 16 (I've heard that having violations can mess with that) then you'll have points on your license. Which means your insurance, which is already crazy because you are young, is even more crazy than usual.

The costs will easily run into the thousands, especially adding in years of high-risk insurance premiums.

The cops have been slow to respond to the surge of illegal motorcycles, but they are more engaged every day. You can defy them, but they will make sure that it costs you dearly.

Go to a local shop and tell them you want an ebike that's legal for you area.