I am just. getting started into programming, and would like to know the best platform/language to use.
Programming languages
Language is often a personal choice.
In Apple's world, there are 2 : Objective C and Swift.
Some swear only by ObjC, other by Swift. IMHO, it is wise to become "expert" in one but also able to at least read and understand the other.
This being said, my personal choice is Swift which is gaining momentum. But ObjC is to be there for a while.
If you are looking for app development incl UI, then Swift is the right language and IOS is the right platform. The Swift playground is interesting. But if you are looking for areas like Data Science, python is also a good language to learn.