To stay accountable, keep track of your reads, swap ideas for books, etc., the hosts suggest joining the Goodreads group. The members of the group are "impressively well-read" as they put it and I totally agree. You can join the group here: www.goodreads.com/group/show/152458-ultimate-popsugar-reading-challenge.
The most obvious one is to go to your local library. They often do not only have print versions of books, but also ebooks you can borrow. Just ask them how it works.
Another option is to get a Kindle Unlimited membership. That one is $9.99/month plus tax. These 10 bucks are worth it if you read a bunch of books per month because you can select from about a million titles and thousands of audio books. You can also test the membership 30 days for free. Check it out here:
(Here you have two options: (1) download review copies and start reading right away and (2) request review copies. The request option requires a brief message explaining why you are interested in a copy.)
(I found this page even easier than Edelweiss+. You can also request review copies or download and read right away.)
Both of these providers offer review copies from various genres, including fiction, non-fiction, historical fiction, romance, mystery / suspense, personal development, and more.