Your first step would be to research your state laws and decide if you want a motorized bicycle or an e-bike. In most states, they are different things. Then you need to research licensing requirements.
For example, while I ride an e-bike to work, I had the idea to go for higher power, mostly just to do it. I then saw that going for a higher power unit moved me into the motorized bicycle class. After speaking to the state police vehicle inspector I came to the realization that it was next to impossible to do. That was not a big problem for me, I have plenty of bad ideas that I don't act on.
Back to the point, step one is to checks the laws where you live. Generally, e-bikes, motorized bicycles, motor-driven cycles, mopeds, and motorcycles are all different types of vehicles and clearly defined in the law. Don't take the word of a person on the internet who is trying to play cute word games, check the laws where you live.
. . . and this is what I commute on, an e-bike:
