When should I get a credit card?

I’m gonna put codependent on my parents insurance I think. Im in a relationship though so we dream of the future. not happening anytime soon. I got birth control. he was saying the other day that I should get a credit card. he’s opening up a credit card account to raise his credit score. he was telling me a negative credit score is basically worse than 0. I got nothing. I have 0. it takes a while to raise it up ig. idk how long though. I’m 21 and still am in college.