If you want a smart watch, find one of the Android compatible models.
You are just asking for a lot of disappointment trying to make an Apple Watch work with an Android phone.
The Apple Watch depends on a lot of the iPhone services over Bluetooth, besides being the owner of the phone number.
For example, the Apple Watch needs to relay all SMS/MMS texting through the iPhone. Android is not going to have the private protocol the iPhone and Apple Watch use for that. And if the iPhone is not with the user, the Apple Watch uses the Internet to talk to their iPhone to handle SMS/MMS texting.
That is just one example. There are other things the Apple Watch depends on the iPhone to do its job.
Assuming you do not want to get an iPhone, I strongly suggest looking at an Android compatible smart watch.