I had been working as a management consultant traveling every week, and wanted to stay home with my young children. Although I have a Stanford Ph.D., I had taken only one computer course, Introduction to Fortran IV with Watfor in 1966. Nevertheless, I had kept up my programming skills. Anyway, I did wind up getting my MCSD and then later my MCDBA. I took them because I wanted to be sure I knew what Microsoft thought I should know. I don't suggest you go my route (unless you love taking exams), but I do think that self-study and passing at least one certification exam is worthwhile.
But I also agree with the other respondents. Get the Dev Edition, practice, and do volunteer work.
Another idea is to focus initially on mySQL. It is pretty slick, free, and much used by startups, who being cash strapped might be more likely to hire you as a junior DBA. All DBMS's are fairly similar; you do the same things with all of them. It's just the syntax that differs some.