I got into software development without any education or prior experience at the age of 25 and learned iOS development. I work as an iOS developer & consultant and I feel I'm doing dead-end freelance gigs, which doesn't feel like they will get me very far. I want to be involved in backend development as well but I don't have a clear path as to how I can make that happen. A mentor might have been very good to have here to at least offer second opinions, but I am unable to find one, since the people good enough to be a valuable mentor usually don't stay in this country(I'm in Turkey). Even if there was, I feel like age might be an issue.
Where and how does one find a mentor? Is it too late to find a mentor after 30?
I will have an interview next week for an iOS role where the company representative said that I will be expected to know basic stuff about Docker, AWS and NoSQL databases. Being an iOS dev, I don't know much about these. What should one know to cover "basic" stuff? What materials would you recommend for learning about these?