Start by googling "university_name degree_name curriculum"

Here is my school's 4 year course curriculum including all senior year elective choices with descriptions of the classes for electrical engineering, computer engineering, computer science, and mechanical engineering.

https://catalog.ncsu.edu/undergraduate/engineering/electrica...

https://catalog.ncsu.edu/undergraduate/engineering/electrica...

https://catalog.ncsu.edu/undergraduate/engineering/computer-...

https://catalog.ncsu.edu/undergraduate/engineering/mechanica...

Take some time to look at the sequence of classes. Some stuff is obvious like Calculus 2 comes after Calculus 1. Look at the classes in common during the first 1-2 years.

I strongly suggest reading every single class description and especially every senior year elective class description.

Too often people think "XYZ sounds cool, that's what I'm going to study" without actually knowing the names or descriptions of the classes they will study.

Circuits 1 was the weed out class at my school. The first day of class the professor said 1/3 of you won't be here next year. He was correct. About 20% of the students dropped the class after the first test. Many of them switched to computer science which I think is a much easier major.

When I see someone say "electrical or mechanical" that is so broad that I feel like you don't have a good understanding of what either really are. That's okay but you shouldn't be making a big life decision with a vague understanding of what they are. That's why I took the time to post all those links for you to read.