Good job just writing and getting the work out, but I have a few ideas for the revision process for you. I'll just help give you some thoughts on ways to go about this by using the first two paragraphs as an example.
"Nothing could be seen in the morning sky as a young teenager cautiously walk[ed] through a long and elegant corridor with fascinating decorations on the wall with evidence of past presidents and the cause of their inaugurations, and the reason of their resignation. [For your first sentence, it's terribly long and does a lot of TELLING rather than SHOWING. If you've done writing before, I'm sure you've heard that and know what I mean. Describe the decorations physically and let the reader decide what they think they are looking at. I.e. "Nothing could be seen in the morning sky as the young teenager cautiously walked down the long corridor. The hallway's elegance was mirrored by the boy's fascination with the presidential decorations. To his left, Woodrow Wilson was writing presenting fourteen points to a League of Nations, on on his right, Franklin Roosevelt grinned unseeingly at the viewer from a fireside." Now, while that's just an example, do you see how you can get a lot more across by showing details?

] The boy wore an unbuttoned vest jacket, with a black shirt inside, and [sic] blue jean[s]. [Again, don't just tell what he's wearing... make it useful somehow and a side effect of some other point you want to get across. I.e. "The boy unbuttoned his vest jacket, bearing the black shirt underneath to the hallway. His shoes poked out from under his jeans, but echoed in the quiet air before morning."] He overlooked the entire wall section between two six-paneled wooden doors. On the top of the doorknob was a set of numbers, and the same to the [correct door OR door on his right].
The boy tried many numbers before [before what?], not knowing how many digit the password [was], or what number in what digit [I don't even know what you're trying to mean there... perhaps you need to explain the lock better]. But he did know one thing; under the doorknob of the left door was a crest of some sort. It resemble[d] a sword crossing with a sword, but there [was] a shield in the middle, redirecting the sword paths from impaling each other."
So... your tenses. You switch between present and past within the same sentence. Choose one (past tense is by far most often used in books/stories) and stick with it. Also, try to show and not tell. You're very close to getting it right because you DO provide the reader with details that help flesh out the scenes which is GREAT, but now remember to send us those details in an interesting way. I find it's easiest to do this by action within the scene and by avoiding the "to be" or other static verbs. Instead of "She was happy, and said 'yes, of course!'" where that sentence just tells, you can show with "Her heart beat a little faster as her face broke into a lopsided grin. "Yes!" she cried out, unable to contain her excitement. "Of course!'" Which one is stronger? Notice the verbs. The first one uses "to be" and "to say." The second version uses "to beat," "to break," "to cry," and "to contain."
Anyway, hopefully there's some helpful constructive criticism you can keep in mind as you continue writing.
Also, I'd like to know what you mean by "officially a book writer." Do you mean to say you've published something? Or that you are announcing your intentions to write a book rather than fanfiction?