You can't realistically do iOS development without knowing Objective-C; its just no feasible since all Apples frameworks are written in it, all the open source libraries use it, and all of the stackflow answers are for it. And fortunately, it is not a bad language.
Swift is a much better language, at least potentially. It is still a bit rough to use. But it is sure to replace Objective-C over the next few years, so you would be a fool to ignore it.
To address the larger question - you should get some formal computer science instruction if you ever expect to land a job. You have to have something on your rÃ©sumÃ©.