If you already have a library card, you have free access to digital collections here:
https://www.tulsalibrary.org/books-music-movies/digital-collections
My favorite sites are Overdrive (for ebooks and audiobooks), RBDigital (for audiobooks), and CloudLibrary (for ebooks and audiobooks). You will need to register for each of these sites using your library card number. They also have apps for phones and tablets. Please email me if you have trouble accessing these digital resources.
To sign up for a library card, go here:
https://www.tulsalibrary.org/get-a-library-card
Once you complete the sign-up form, you will have immediate access to the digital libraries above.