I want to take computer science for my bachelor's degree, which programming languages I should learn beforehand

Question

I already learned Swift, Java (partially), JavaScript, HTML

Answer 1

practicing definitely. also, youtube videos, this app, codecademy & sanfoundry to strengthen your already learned skills.

Answer 2

What is best is to practice coding, the language you pick up is less important than actually exercising your skills at creating software.
If you like java, just try out more complex challenges using it. alternatively, python is quite fun.