As a retired FBI agent, I am often asked about what it was like in the FBI or how to become an FBI agent. There is too much to say about those topics to answer those questions here, but one of the things I always say is to read up on it. Read books, not just websites or pop culture sources. I often recommend the book FBI by Sanford Ungar. It was published in 1976 and is not available in electronic form, but you may be able to find it in your local library, since it is something of a well-recognized standard. If you have trouble finding it, the subtitle is An Uncensored Look Behind the Walls. Here is my Amazon review:
This book was ground-breaking in its time. While hardly current, it nevertheless provides a thorough and often-entertaining history of the finest law enforcement agency in the world. I bought a copy when it first came out in the 1970s and I still pull it off the shelf and refer to it from time to time, since I now write about the FBI myself. It makes excellent reference material, but it is also very readable. It’s written in a journalistic style, which is unsurprising, since Ungar was a print journalist when he wrote this book. I recommend it.