I was stuck for a long time too, couldn't decide which field of engineering I wanted to go into. Two things helped: Going through the university modules of a possible list of courses I could like. It might not tell you much since you haven't even started studying those modules but a lot of times, people have wrong assumptions of the content of a course. Seeing the modules helps clear that up.
The second thing I did was to make a list of the possible careers you could go into through a chosen degree. Then, I watched a lot of 'Day in the life of...' videos. A lot of them will tell you the pros and cons of the career, how much they make, etc. In the comments, you'll be able to read the experiences of those working in the field. There are also 'Day in the life of...' videos for those studying a course. You can look at such videos too.