Is it bad to approach women in public?

So for some context I am 18 and currently at my first year of college. Because I recently moved from my home state I dont really have any friends but have been trying to push myself to get out and talk to people more.

Anyway me and another guy I recently met were walking to our next class on campus and I saw a girl which I honestly thought looked nice. She also had a Beatles shirt on and was going the same direction so being someone who also listens to the Beatles a lot I decided to start a conversation.

We talked for a couple minutes as we walked to our next class which was in the same direction and when we split ways I asked for her number because it seemed the conversation was going well. She said no and that I am not her type so I just said word for word "no worries hope you have a good day anyways"

However, after the interaction my buddy who was walking with us called me out and said that I should not do that as I was probably "making the girl uncomfortable" and that she "did not consent to be approached"

I said that "its not like I came up from behind her in a dark ally" I mean we were in public in the middle of a buisy college campus. I also said that "I dont think I really made her uncomfortable and that she could have easily walked away at any time."

I dont think I was being unreasonable but is it really not ok to approach people anymore? I feel like I was being completly reasonable and acting very normal.

I just want to know if this is something socially acceptable so I know if its ok in the future. Whole thing has just left a sour taste in my mouth as I dont want to be viewed as a creep or a weirdo for doing something I thought was completly normal.