Doomed as a 3rd year student

Guys I am...well unpad (not really)

So, I was a pcb student and took bca as my degree in college.

Now in August I'll start my 3rd year and well in the last 2 years I did not focus or read a lot for BCA as a career.

So please let me know everything that you guys think I should know as a student of bca

1. What is dsa, and why does everyone focus on it so much ?

2. If I have intention on choosing data science as my career what all should I know. (Please do tell me this 🙏🏻🙏🏻)

Ps : don't roast or judge me, please help me