Welcome to the forum. Hope you enjoy it around here.
What format did you read the first book in?
So far, the only ebook format I've found is in Kindle; which doesn't help you at all. You may be out of luck for an ePub version.
As to the library, you can only use libraries you belong to. Your first step is to see if your library offers ebooks. If it does, then join. After that, visit the ebook page and download Adobe Digital Editions and OverDrive Media Console to your computer.
Also, check to see which other libraries your library has reciprocal borrowing agreements with. Joining them gives you even greater flexibility with borrowing books. My library system has agreements with over a dozen other library systems and I've joined more than half of them. It comes in handy when the book you want is on a waiting list. Checking the others might find it available or on a shorter waiting list.
Feel free to ask detailed questions about setting up your library account and downloading books. It's really quite easy.