I majored in Administration of Justice and minored in Sociology in college. That may be the better route to go as there will be elements of overlap with both areas of study and you may experience unnecessary redundancy. My suggestion would be to obtain your undergraduate degree with a plan to then enter a joint degree program which would afford you two advanced degrees in a shortened amount of time. As an example you could do a three-four year program in business and law (MBA/JD) or Social Work and law (MSW / JD). If you are already on your way to completing the double major listed you can look for careers in the criminal justice system (prosecutors, defense attorneys, litigation), criminal justice reform, non-profits and politics. Re: a sociology degree, you can obtain further certifications and work in education (private and public), non-profits, public policy, etc.
Either way, you are going to be paying a considerable amount for your degrees so try to get the best and broadest bang for your buck! I recommend doing extensive research and finding people who work in the fields / professions/ and jobs that you are interested in, and asking for their input.
Judges are either elected or appointed depending on the city, town and state, and that only happens after completion of law school, passing the state bar, and often years of experience.
I was waiting to see if anyone else was going to answer this first!
The idea of "double-majoring" seems to be very common lately. However, when doing so, students should look for two fields that are somewhat different, yet can compliment each other in a chosen career. For example, Accounting might be a good second major if one hopes to go into Grant Writing or Urban Planning or other Budget-intense jobs.
I honestly think that Criminal Justice and Sociology are too closely related to double major in. I don't think it will open up the job field to you any more than a single degree in either field would do.
If you are seriously contemplating law, think about all the complexities of law that are out there, and where you might see yourself. For example. Environmental Law might require the ability to understand concepts like Climate Change/Global Warming. Criminal Defense may require that you understand how the body metabolizes alcohol (DWI trial), Personal Injury might require an understanding of traffic accident reconstruction. Employment Law might require an understanding of Non Compete agreements. What am I getting at? If you want to be a lawyer, try to get some solid background in some of the complex areas of knowledge. At the same time, challenge yourself with speech/debate classes. I strongly recommend classes in Logic, Latin vocabulary, etc. The difficult classes in college will help prepare you for law school!
Becoming a judge usually requires experience as a lawyer. You will also need to network. Some positions are appointed, and some are elected. In Texas, most are elected.
Becoming a lawyer requires a 4-year degree, followed by 3 years of law school, and passing the state bar exam. It is very hard work, and you have to truly want it in order to successfully get through it.
An alternative you might consider is becoming a Paralegal. Paralegals work for attorneys, and, while the starting pay is not great, it quickly goes up. You can do all the research, writing, etc that the lawyers do, depending on what assignments they give you. However, you cannot give advice, set fees, represent clients, or things like that. If interested, shop around! There are different programs available. You can get a Paralegal Certificate, an Associates Degree, or some other route. Try to find a program approved by the American Bar Association (listed on their website), as some of the other programs have reputations of not being that great. In Houston, check out the program at Lone Star College - North Harris.
Best of luck!