In order to go to the exam and do really well, you need to prepare. Reading is an extremely important part of the preparation. You will gain agility, vocabulary and comprehension skills. You can read whatever you like, try to mix the types of reading: read short stories, books, articles, news and analysis.
Short stories: https://blog.reedsy.com/short-stories/
More short stories: https://americanliterature.com/100-great-short-stories
Also, I am quite a book guy: buy a book online second hand and when you are done give it to a friend.
In English Please – How to learn faster! Lessons from Neuroscience. (Spanish) (this will help you learn better and use your time more effectively)
Official practice papers: https://www.cambridgeenglish.org/exams-and-tests/first/preparation/
Non-official: https://www.flo-joe.co.uk/fce/students/tests/ (some content is repeated from official exam)
Official book of Cambridge: https://eslcafe.ru/wp-content/uploads/2018/10/Cambridge-papers-FCE-1.pdf (PLEASE NOTE: The exam changed in 2015 and combined Reading and Use of English – however, this book is great for you to use to practice)