the part where the bass kicks in after a period of calm?
i dont use FL studio, but the DAW doesnt really matter, most tricks you can learn about music production will be useful across all DAWs.
i suggest watching youtube videos, reading articles/books/e.t.c. asking specific questions in forums like this and general googling.
there is too much to list, but learning about EQ (equalising), compression, mixing,... might be a good start.
there is a whole lot of stuff to learn if youre serious about music production. just be patient
ask questions, do research and more importantly practice and HAVE FUN. if you have the drive you might well be the next aphex twin.
Parricide linked something that should give you an idea of what mastering is.
Bass drop is usually what follows the build up (after most of the energy has been built.)
As for fl studio and making your tracks better, find out if fl is something you want to stick to and try out demos for other DAWs. Once you decide, take time to watch tutorials and learn the DAW inside and out. No one tip will make you sound professional but experimentation and hard work will get you there over time.
For the number one track. Don't worry about that. Enjoy what you do and work hard and aspire one day to get there but produce because you like it, not for popularity/fame.