Yes it's a good plan. The practice of law requires a lot of writing.
I think going out into the world and getting a job before law school is a great idea. You can get some work and life experience, and also see if maybe you just want to do that (and don't end up going to law school at all).
Law school is a BIG commitment. It takes 3 years, costs hundreds of thousands of dollars (I have $200,000 in loans), and at the end it is only useful if you want to be a lawyer for the most part. A law degree doesn't teach you anything else besides how to be a lawyer.
So try your hardest in college, get good grades, and try to get internships for writing/editing. Then after you graduate go and get a job.
If you don't think you want to go to law school, you can first go and get a job as a legal assistant or paralegal. That way you can get experience, earn money, and see what the practice of law is about before you make the huge commitment of law school.