Objective-c or Swift

First of all, this is totally up to you. The note by Wes Aday, about "random stranger", is quite correct.

But what to do? This is the usual self-referenced problem: to learn if you want to know for sure if you want to learn a language or not, you have to… learn it. This is what you can do: learn the both until you know which one you are interested or not. You can always unlearn if you want to.

Everything else depends on your goals, and one important part worth mentioning is: do you want to learn programming or not? Yes, it's possible to use use some language without really understanding programming in general, something which I would not advise though. So, if you want to learn programming, you should also understand that both languages are not standardized and rarely used outside of Apple world, which is itself pretty much self-isolated from the rest of programming (even though the "rest of programming" is open to Apple systems). If you add your PHP (which hardly can be considered as "serious" language), all three languages will hardly give you enough background to understand programming. But don't you take learning yet another language too seriously?

Alan Perlis wrote:

A language that doesn't affect the way you think about programming, is not worth knowing

—SA