Should I buy a kindle?

Heyy everyone First of all I heard that you could download books on epub and share that to your kindle is that true?

Is there a difference between a normal kindle and paperwhite beside the storage and size?

Is there anything else/ other benefits I should know about a kindle before buying?

And is the usage like the phone like how long will it take for a kindle to fully ware out if I’m gonna use it on the daily?