I was in this situation last March. I had no native experience with only years of ruby and javascript under my belt.

I decided to begin my journey into the Apple world by starting with Objective-C. I made this decision because of the rich availability of learning resources, Stackoverflow's engaged community and the maturity of the language.

I moved over to Swift this January, and the transition couldn't have been better. I know I will take flack for this statement, because it isn't entirely true but: I feel like Objective-C and Swift are related to one another as Coffee-script is related to Javascript; so the time spent learning Objective-C was not wasted and only made my appreciation for Swift greater.