To learn New jutsus and rank up is very simple.
To Rank To Chuunin Level You Must-
* Have Done 10 Mission Reports
* Passed Chuunin Exams
Jonin Rank-
* Must Have done 25 Mission Reports
*Passed Jonin Exams
Anbu-
*Must have done 40 Missions
*Passed Anbu Exams
Kage Rank-
* Done 60 Missions
*Passed Kage Exams
Sage Rank- (senjutsu Level)
*Done 80 Missions
*Passed Sage Exams
God Level Shinobi-
*Done 100 Missions
*Passed God Level Exams