I’m learning American Sign Language by myself, but I’ve realized what’s the use of it?

So, where can I use my knowledge of sign language? I don’t know any deaf people, and I live in the Philippines( I don’t know if we use ASL here or some other sign languages) .

I am interested in learning sign language. Would it be worthwhile to teach myself from a book?

There are no teaching services in my area that I take classes for or anything similar to that. I know that there are books for sale on learning signing, but how good are they? .