Two requirements for law school admission–great GPA and high LSAT. Doesn’t matter what you major in to get there. You need to go to a well regarded law school. And do well. You need to be near the top of the law school class. Many grads don’t have jobs because the schools they attend don’t have the credentials or they didn’t make the grades. Our state has a good number of law schools but only 3 or 4 from which firms hire. Do your research. Don’t attend a second-rate law school and accumulate debt.
Pick a major you would want to have a career in case you DON"T go to law school. And keep your grades up. Law requires analysis and writing ability both.
As for doing film on the side as a career after law school–I don’t see it happening except strictly as a hobby It’s too time-consuming. But hobbies are great (and soul satisfying) and I turned photography into a small business at one point. Just part time but it still took study and contacts. My goal at the time was make enough money to cover my hobby expenses!
I hear it’s possible to get positions in film without schooling (although I don’t know anybody personally who has done that) but so much of the field is contact dependent and I’m not sure where you could get experience/training and develop contacts while working in any other field . There is a definite time crunch.
When my D first started talking about computer animation, graphic novels, creative writing etc. in HS, I tried to steer her towards more traditional paths but after some research into the field I realized how much further ahead she would be career-wise by going to a specialized school. That doesn’t work for everybody obviously
.People talk about needing “passion” for the arts which evokes different images. I’d say “singularity of purpose” might be a better phrase. You have wide-ranging interests so keep exploring your career options.