Hi there, I'm a blind accessibility specialist and now a senior native mobile accessibility coach with Deque. Knowing how to use the assistive technology is one thing, but you'll need to know WCAG and the applicable criteria for native apps if you want to start testing. I highly recommend you check out https://dequeuniversity.com in order to gain functional and in-depth knowledge of the ADA WCAG, Section 508 standards, and international accessibility standards. I learned my tech skills at the Lighthouse in SF years ago after I suddenly went blind in 2014, so they are a good resource for learning skills and getting connected with focus and research studies for local tech companies, but definitely go through Deque University as a priority.