Law is not a good field to get into right now. Don’t go if you’re just looking for a good reliable well-paying career. (There are many other fields that do provide that.) But go ahead and go if you decide you really want to be a lawyer.
To get a sense of how you’d do on the LSAT, get copies of old tests (they sell books full of them), time yourself and see what scores you get. But before you do that, go through a workbook mean to teach you how to improve your LSAT score.
If you’re smart enough to be a decent lawyer, and you have an entrepreneurial spirit, then you can start your own firm and potentially be successful even if you have such low grades that no one would hire you. I’ve known people who have started their own firms after graduation. But it’s not easy, it’s not common, and it’s not for everyone. It is very common nowadays for smart people with good grades to graduate law school without a job.