I’m in the process of getting my masters in social work, and did a lot of research on all the questions you are asking:
For most if not all programs, you need to major in social work or psychology in your Bachelors.
I know of a nice few Jewish people who do Fordham, which has an online option. It’s a great on-campus program, so the online program isn’t disregarded as junk, unlike many online-only programs.
Two online universities which are supposed to be top-notch are UCS (great curriculum, prestigious, very high standards, but also very expensive) and Simmonds, but you would have to do research on how compatible they are for a frum person.
You can take Rebbetzin Bulka’s program in New York or Israel. The social work program only meets once a week, on Sunday, for a full day, so you can commute. It’s an amazing program and you can specialize. (The Drug and Alcohol specialization at LIU is supposed to be their best program. It’s known nationally for being top in that field.) You can try to get an exception and Skype classes elsewhere, but I don’t know of anyone who got such an agreement.
Good luck with your decisions!