I'd see if you can contact someone living in the area (an organization for the Deaf for example) and then see if there's a way that you can connect via online video chat with someone living there who is fluent in the signed language you want to learn, as well as English (since you're an ASL student I'm assuming you're more fluent in English than ASL at this point?)
Trying to learn a signed language (versus learn a few signs) from a book etc is really impossible - you need to have a moving visual (or tactile if LV/Blind) "model" to learn from and someone who can observe how you form the signs etc and correct any issues.
Personally if the idea of learning another sign language is "so I can some day travel and communicate etc with the people there in their native signed language" I'd really recommend getting a strong command of ASL first as having a solid signed language base will make it MUCH easier when learning an additional signed language as you'll already have a strong understanding of how a signed language worked, and the basic "rules" that govern signed language (ie how to use signing space, signing in a smooth understanding way etc).
Attempting to learn ASL and another signed language simultaneously while you are living in an area where one is basically not used at all is likely to end up causing more issues, than helping.
Hope that helps
