When I moved 3000 miles across the country to go to grad school at UCB, some people thought my biggest adjustment would be due to the change from east to west coast. Personally, my biggest adjustment was transitioning from undergrad to grad. Opening up to upperclassmen about my worries and reading online PHD guides has been both emotionally grounding and constructive in helping me understand the new skills I need to be a PHD student.
Below is 1) a compiled list of advice from upperclassmen peers, 2) An excellent TED talk about the research process, and 3) recommended links to PHD guides.
Don't be afraid to ask questions, even if they're dumb. People who are willing to share ideas and ask questions tend to make so so much more progress than people who try to figure out everything on their own. It's really remarkable the difference. It can make it hard for people who are particularly introverted sometimes. Don't worry about looking dumb. If you find yourself in an environment where one or more people make you feel bad for asking a "dumb" question or not knowing something "obvious," consider changing that environment. In my opinion they have done you the favor of pointing out to you that they suck and aren't helpful to have around. However, almost all grad students know what it feels like to not know anything and are very cool about it. Also next year the new first years are going to be asking youthese questions, so it's good to learn them well enough now that you can explain them in the future.
"Don't compare your chapter 1 to someone else's chapter 20." It's incredibly easy to experience imposter syndrome here. I think in our last survey something like 98% of students said they've struggled with it. Different people in EECS have very different skill sets based on what they've put their time into. Someone who has put more time into learning a subject than you will know way more than you do. That does not mean that you're stupid. A friend of mine entered grad school at Stanford EE without knowing what an eigenvalue was. He got his PhD a couple years ago in autonomous driving and now works as a consultant for McKinsey. You'll be fine.
Be ok with being overwhelmed. You're probably going to sit in a lot of talks where you have no idea what's going on and everything looks impossibly complicated. Know that any subject is just a series of incremental simple logical steps that build up to something complicated. That's how the speaker learned the subject, and that's how you'll learn the subject if you decide you want to. Also if you've learned the background information that the talk is on and still don't understand, that's almost definitely because the speaker didn't do a good job of communicating. That happens a lot.
In general finding a healthy balance between the academic interest of your work and the potential applications of that work can be hard. But in terms of being successful, I would say most successful students are not trying to revolutionize the world with their thesis. We are students. Our goal here is to learn how to think deeply about a subject and to learn how to make connections based on that deep understanding. Once we have those skills we can apply them in future jobs to important applications. If you try to do something world-changing with your work before even learning how to do effective research you'll probably end up stressed and paralyzed. Just have fun with whatever projects come up that seem interesting.
Have a hobby. Most successful students have a hobby that lets them de-stress. Off the top of my head here are some examples: tango, a capella, running, volleyball, hiking, sailing, scuba diving, video games, climbing, gardening, baking, coaching middle school soccer, etc. A hobby that involved some level of cardio exercise is particularly useful; many of us have had the experience that exercise makes our brain power last a bit longer.
Professor Uri Alon - Why Truly Innovative Science Demands a Leap into the Unknown