Hi Dekota,
While I wouldn't want to discourage anyone from self-improvement by way of further education, I don't know how well you would be served by the paralegal program you're interested in. I agree with Anita that these courses won't qualify you in CA or SD as per their website:
State Licensing Requirements
In the States of California and South Dakota, a Paralegal Diploma will not qualify graduates for employment as paralegals.
I would also say that many law firms require some form of on-the-job experience at a minimum in order to even be considered for a position. I would say that by going with Penn Foster you might have a tough time when it comes to getting clients.
Have you looked at any of the courses at VA Classroom? As the courses are for VAs to expand specific skills that are usually in high demand, I would think it might be more beneficial in the long run.
Good luck and let us know what you decide!