For SDE with < 1 YOE, do interviews have system design questions? If so, what are some good resources to get started?
Yes. They do ask. Grokking the system design by educative.io is one of the good websites to prepare.
Don't think square has system design interviews for new grads
It’s mostly object oriented design
They do but they don't matter very much, so don't sweat it.
Actually they do. I was rejected because of below par performance in system design interview.
I know someone who got hired at L4 after PhD despite their terrible system design, the expectations for industry inexperienced folks are really pretty low. Not impossible to fail, of course, but spending a couple days reading up and practicing a few questions should be enough, which is quite different from leetcoding for months.