Instituto Cervantes has some graded books here: https://cvc.cervantes.es/aula/lecturas/
This blogs gives you more material: http://blog.readlang.com/ultimate-guide-to-spanish-websites-for-beginners-to-practice-reading/
I couldn't know your Spanish proficiency, so, I would assume you can write and read simples textes for B2 learners.
Take a look at this:
It´s an audio book with simples structures but with a challenging vocabulary ;)
Some things couldn't have sense at the beginning but keep in mind this is a poem!
If need a hand, just let me know ;)