You don't need to learn all your characters moves... Just have a go to bread n butter and mixup and understand your character's strengths.
What you DO need to know to be really successful in Tekken is pretty much every other characters' BnB's and mixups for all the characters... (this is why players who have played the series since the old days are at an advantage, since many combo/mixups stay the same and they just need to learn the new characters)
You have to understand parries/reversals, startup/recover time, and breaking throws, and wake-up game...
And since its a 3d fighter, there is even sidestepping techniques to learn as well..
(this is why I never tried to take Tekken seriously since I don't have the brain capacity to be any good at it)