Dont hate but i just started . Im lev3l 21 and every level still havent a skill tree to put points where i want. Doesnt exist hu?
Just keep leveling you will get them as you unlock difficulties.
There is no skill tree in Diablo Immortal.
But once you reached Lv60, paragon system will be unlocked and there you can put your the paragon point for paragon passives.