How to start modeling?

So, I'll be turning 20 soon, and I've been told several times that I should try modeling. I have zero experience in the field and therefore don't know exactly how to best get modeling agencies interested.
I don't like posting photos of myself on Instagram, even though I know it would be beneficial.

About myself: I'm 5'4"/5'3" and have a normal build, relatively slim but not super thin. What's the best way to get started? Are model scouts still regularly on the streets these days, or are they only online? I'd love to hear your thoughts! 🙂