You need to complete new plot/elite instances and gain battle points for your progress system.

After having completed 3 pages, you will get the Jounin rank.

Hi!
I hope you mean the rank in character tab,because I'm going to write that down. To earn those rank,you have to unlock the "Progress" tab (unlocks at lvl 24). To gain a new rank,you have to earn so called "Battle Points". Battle Points can be earned by completing Instances(Both Plot and Elite). The maximum amount of star that can be obtained per instance is 3(1 for completing it,1 for killing all enemies,and your earn 1 star if your death don't surp@ss 3(so the max is 3). To earn a new rank,you have to spend these battle points and gain new levels on this progress line. Once you completed a rank's progress line(You will see it on my picture called "Progress") you have to do a so called "Upgrade Test". If you p@ss that,you will get a new rank.(From Genin Chunin, From Chunin Jonin etc.)
I hope I could help.
~Spill~

:D:D:D:D:D:D:D

Hey where can you find the progress system 'cause it flashed once and I ignored it and now I ca't find it so please help

character page, on the bottom, in the center, right below your list of skills.