Research — talk to the Undergraduate Research Program office in Mary Gates Hall. “Getting started” presentations are offered every other Friday in the summer and every Friday in the fall term.
Getting good grades — you were smart enough to get in as a transfer. Just don’t slack off, and go to office hours or tutoring when you recognize that a class will be tough.
Standing out — When you find something you’re really excited about, commit 100% to it.
Making friends — Not gonna lie, this one takes time. As far as my friends’ kids go (I’m a parent), there hasn’t been any one particular thing that worked. Just try to be involved in things — it could be an on-campus job, a club for your major, a research lab, a small seminar class, study group, etc. and keep trying. If you play an instrument, join the band or orchestra.
The CSE 390T transfer seminar is designed to help you get acclimated. I’m signed up for it as a junior transfer - class is 2 credits, and 1 credit of that counts towards CSE senior electives. Seems both helpful and pretty easy. Looks like you are already signed up for it, though.
Maybe get the textbooks now and use the web resources to get a head start on the material.
I hear that joining the ACM chapter is a good move but don’t have any additional insights.