When I was in undergrad, I wish someone would have told me how important it is to balance my time and prioritize things other than school.
Whether it is hanging out with friends, going to a club meeting to connect with peers, taking a break to go to the gym or spending some time to cook or play some video games, it is really important to have the life part of work-life balance.
I remember staying up really late to study or complete assignments, and the next day I would wake up exhausted, unmotivated and with a really horrible assignment handed in. Using a planner to organize my time was super helpful and changed the game for me. I started setting boundaries with my time and not working past 10 pm, even with studying. Doing so really helped me develop some social networks and develop other hobbies that I normally wouldn't do (like painting).