Yes, you do, eventually. If you never learn phrasal verbs there are going to be huge gaps in your vocabulary knowledge. This could cause you to be unable to express yourself properly or to misunderstand other people.
“But you could just use normal verbs, couldn’t you?”
You could in some situations but not in others. There are differences in meaning between some phrasal verbs and their non-phrasal alternatives; sometimes it is small but sometimes it is vast.
In my opinion, it is best to learn phrasal verbs from reading or listening material. For the phrasal verbs you read or hear and try to understand what they mean and how they are used.
In the following news stories, there are several phrasal verbs. If you don’t know them, I recommend taking notes, trying to use them in a sentence of your own and then trying to write something longer. When taking notes of the phrasal verbs, notice whether they are split or kept together.
Ben Flower Faces Tribunal Over Punch: look into, liaise with, decide on, go on, hold against, charge with, deal with.
Vietnam Vet’s Prosthetic Leg Stolen At Philadelphia Eagles Game: look for, run off, end up.