When creating your character, a must is to have jutsus.
In the academy, EVERY ninja is taught the following jutsus:

Bunshin no jutsu
Henge no jutsu
Kawarimi no jutsu
Very basic genjutsu

When you are getting your character profile approved, you may also request a few genin jutsu to teach you in the academy (but get greedy, or if you want very powerful jutsu, we just won’t give you them!)

After you leave the academy, and get assigned a jounin, the only way you can obtain more jutsu is to:
Have your jounin teach you

Request a tutor at the council office (we will review your missions to see if you have earned it)

Special jutsu that, for instance belong to your family, or are bloodline limits, but generally only YOU know, you must have it approved in the council office, before we put you in a quick training roleplay (you can’t just walk in, then walk out and master it!) This applies to forming jutsu as well.

There is no limit to how many jutsu you can learn, and no limit on rank/difficulty for jutsu (Sasuke’s a genin, he knows Chidori, Neji’s a genin, he knows Kaiten), but bear in mind you don’t have infinite chakra! Godmodding will not be tolerated!