Hey there,
I'm an aerospace engineering student so I'll try to explain the differences based on what what my friends' experiences.
So the difference between comp sci and software engineering is that comp sci seems to be a lot more theoretical and mathematical, looking at the math logic behind things like machine learning, and if you want to specialise you can go down the route of security. Software engineering is a more practical version of comp sci, looking at software testing and creating new software systems. Software engineering also has an entrepreneurial/start up side since you'll also need to promote your software systems to clients. Electrical engineering is a lot broader from working on things like developing phones to developing electric cars and working on electric components in planes.
Hope this helps!