First, I recommend you write why you want to be a lawyer. Try to state specifically your reasons. It would be great if you can show your writing to a lawyer that you or your family knows who will give you feedback.
If this is your chosen path, wherever you attend college, do well and take challenging courses. Your major is not as important as it would be if you want to pursue med school. But, I do recommend you take a creative writing course, a history of the law if it is offered, a sociology course and one or more political science courses. But, just in case you change your mind, take some courses that will help you have a career after undergrad, such as computer science or business courses. A very good GPA is important.
In undergrad, get involved in the school community such as doing volnteer work and joning a club that includes others interested in law school. It is good networking. Get to know faculty members so you can ask for a recommendation from your favorite prof or advisor.
You will need to decide if you want to attend law school rigght after undergrad or take a year or two off to work to gain experience and save some money.
You will need to take the LSAT. Check the LSAT website for timing of when to take the test based on when you plan to apply to law schools. You may feel the need to take it more than once if you don't like your score after the first try. This is pretty common. Study practice questions and take one or more practice tests to be ready for the actual test.
You want to go to a good law school (hopefully a top 25 school) so GPA, LSAT scores, recommendations and what you accomplishes in undergrad are important.
Good luck. You will do great.