You can major in anything to be a speech-language pathologist. SLP usually isn’t an undergraduate major; a common undergrad major is communication disorders, but there are a lot of other things you can major in and go to school for SLP. Most programs simply require that you have broad coursework across the life/biological sciences, social/behavioral sciences, physics & chemistry, and a course in statistics. (There are a few programs, like Boston University, that require courses that you would only get by majoring in communication disorders as an undergrad).
You can minor in pretty much anything - your minor probably wouldn’t really have any bearing on getting into graduate school. However, there are certain majors that might complement well. Bilingual SLPs are in pretty high demand so majoring or minoring in a language and becoming fluent in it - fluent enough that you could conduct therapy in the language - would be good. ASL could be a good major or minor if you were planning to do speech therapy with children with hearing impairments or who were deaf/Deaf, but keep in mind that a lot of colleges don’t offer ASL classes (or don’t have a robust enough ASL curriculum for you to attain fluency. Actually, in my experience the college most likely to offer ASL are community colleges; many of them offer ASL certificates and ASL interpreter certificates). Psychology could also be a decent complementary major or minor.
A close friend of mine is a bilingual SLP in NYC schools. She double majored in communication disorders and Black studies in undergrad; she’s bilingual because she’s Dominican and grew up speaking Spanish and English in her household.