For me, the easiest way to learn is surrounding myself with sign language. I’m hard of hearing and learning just in case I go deaf, but I memorize the basics first (letters, numbers, colours). Then sign things as I see them so that I don’t forget. Learn in the way you would teach a baby. When I get stuck on a word, I have an app called sign school that reminds me how to sign they have an ASL and BSL option. The signs are shown in quick videos but you can slow them down to learn more easily