Hello guys,

So I'm relatively new on Leetcode. I joined when I got an interview at google and I've been solving questions ever since.
Before my interview, I was told by my recruiter that I wouldn't be getting any systems design interview and when I saw the design segment on the google card, I skipped it because I assumed that was Systems design.
On the day of my interview, I was asked a question about designing a class, which I performed very poorly on.

I've been asked to take extra interviews and now, I want to study class design but I don't know how to go about it.

Do i just start solving questions on it? Are there rules to look out for? Materials that can help me? How would you suggest I go about it?

Will really be looking forward to your answers.

Thanks