Shinobi are the ones that endure.
They are people that have chosen and are prepared to endure whatever is thrown their way for the sake of that which they hold dear. For some that is their beloved village( Hiruzen), for some it is a person that they dear (Haku) and for some it is their dream. (Sasuke)
They are people that have chosen to defy the world and it's limitations. ( Gai & Lee) They are people who love ( Obito ) They are people who sacrifice everything for the greater good (Itachi) They are people who seek to change the world ( Nagato ) And they are people that get scared, confused, anxious... They are people. People who chose to endure, who choose to fight back. That is what a true Shinobi is.
Five basic Elements are : Wind, Earth, Water, Fire, Lightning. It is chakra transformed into a specific elemental state, each having its advantages and disadvantages. Nature transformation is generally used along with Shape Manipulation in order to preform various Jutus.
Ninjutsu itself has no Element. A Shinobi merely uses his pure chakra along with hand seals if necessary, combined with Shape Manipulation in order to perform various Jutsu's that have no elemental weaknesses or advantages.
I want to learn Ninjutsu because it is very versatile area that I feel every Shinobi should master. It provides it's user with many different ways to pressure his opponent, and to be honest, Shadow Clone Jutsu is one of the most useful Techniques in my opinion.