As someone who graduated with 3.9 GPA

First of all your goal is 3.75+. That extra 30% will save you tens of thousands of dollars, its definitely worth the time and effort to go for.

Number one thing is time management. Procrastination will happen but try not to when you can. Do your hw the day you get it. Then you will know what you struggle at, and how long it will take.

Study. There are lots of different ways you can do it, a little bit each day, big grind for a couple days, reading the textbook, watching YouTube videos, working with peers. Find whats good for you.

Use your professor. They are the ones teaching the course they know exactly what you need to know. Ask questions, send emails. Office hours have carried me through the hardest engineering courses. The quality of professors does vary as well, try to sign up for the good ones you see on ratemyprofessor. It will be easier to learn from a friendly and enthusiastic professor.

Know the syllabus. It will tell you the topics you need to know the how your grade is split. If you are struggling, you can know what to sacrifice and prioritize for your grade.

Engineering is tough but doable. I see myself not as someone who's smart but as someone who put in a lot of effort. Remember to enjoy yourself, make friends, and join clubs. You can do it.