How should I decide on a major?

So I was deciding between 3 distinct areas and what I factored in was career outcomes personal interest(will you enjoy it) previous involvement. Due to that, I decided I want to do engineering (civil). It has good career outcomes I'm really interested in, I feel like Ill will enjoy it and I have some STEM ECs.

(Previous involvement is something that is considered at selective schools for reasons if you like I can explain if you ask.)

Also, check to make sure what you want in a school includes your major.

I can't answer the last 2 questions but here are some helpful links regarding the 1st.

https://www.thebalancecareers.com/best-jobs-for-communications-majors-2059631

https://www.bestcolleges.com/blog/what-can-you-do-with-a-psychology-degree/

https://www.thebalancecareers.com/top-jobs-for-finance-majors-2064048

Also try to have your major match up with other post-college circumstances. If you want to live in the midwest don't become a marine biologist for example. Also you can always decide to apply undecided and then decide on 1 of the 3 majors but you can also switch to a different major but that varies in difficulty depending on the school but more or less all schools allow it.

Also one last thing to consider is standout features of 1 that isn't a characteristic of others. Like communications may have xyz thing that you love so thus you major in comm(whether this be a task traveling for work etc). Also consider if you get a minor in something as that can provide a back up career option.

Really hope this helps and feel free to ask for clarification as Id be happy to help. Good luck!