You can try looking for a deaf school near your area that may offer classes that are less expensive or more accessible than college classes. There are also some good apps out there with vocabulary and such, but I haven’t found any that go into the details of how the grammar works. I think it’s awesome that you’re wanting to learn, but also be aware that (as with any language) ASL and the Deaf community come with a rich history that needs to be respected. Be careful not to take ASL or the Deaf community for granted when you embark on the journey of learning this new language. Good luck!!