I have been like you (i.e., wanting to develop iOS apps) for the past 2-3 years and since I haven't really devoted enough time and energy to this project, I'm not much further along than I was then. To clear up a little of your confusion, I have learned a few things over the past few years. XCode is what they call an I.D.E. (Integrated Development Environment). It is software for developing all things Apple -- i.e., apps for Mac, iPhone or iPad (or Apple TV or Apple Watch). You need that one application installed on your Mac in order to develop apps for any of those platforms. When you first start XCode, it asks you what platform you're developing for, and then you're off and running. Swift and Objective C are two choices for PROGRAMMING LANGUAGES, used to write your application programs. When you make an application on ANY of the above platforms, there are two general things you're creating: (1) The interface design, or the way the application LOOKS. That part is done using the tools in XCode. Dragging and dropping buttons, labels, artwork, menus, etc. onto the screen and previewing what it's going to look like. (2) The program logic. In other words, if you make a tip calculator app (like the other 500 tip calculators on the app store) it will need an interface for the user to interact with (created in XCode) and the logic of it will be the part that takes variables (like the total cost of the meal, the number of guests, the percentage of the tip) and CALCULATES the actual tip, the amount each person owes, the tax (depending on the state you're in, which may be another variable), etc. The Swift or Objective-C programming is used to work out this part of the software. Now, of course, the programming is also used to allow your data and calculations to interact with the interface, and there's definitely some overlap, but the main idea is that you need to understand COMPUTER PROGRAMMING (probably in Swift, since Objective-C is becoming obsolete in the future) AND the workings of XCode. Learning to use XCode is like learning to use Final Cut Pro or Photoshop, except much more complicated. It's a very heavy duty application capable of literally THOUSANDS of different functions, and the best developers know it like the back of their hands.
I HAVE begun a number of structured learning programs and there are a few that stand out as providing exactly what you're looking for.
One of the best resources out there for a total newbie to Xcode, Swift, Objective C, etc. is the course on Udemy.com by Rob Percival. Specifically, check out this one:
https://www.udemy.com/the-complete-ios-9-developer-course/
If you search on Udemy, you'll see that he now is offering The Complete iOS 10 Developer Course as well (which uses Swift 3 instead of Swift 2), but since iOS 10 is still in beta, you need to be a beta tester to even START with that course. Or, you might want to wait until iOS 10 and XCode 8 and Swift 3 are all released later in September, and THEN enroll in that course instead.
https://www.udemy.com/complete-ios-10-developer-course/
Alternatively, if you don't like Rob Percival's teaching style, I have found the Lynda.com courses on iOS development to be very well done and thorough, but you need to sign up for a Lynda.com membership. They actually have a series of video courses, when put together, make up what they call a "Learning Path." In theory, if you follow the path, step by step, you will become an iOS developer by the time you're done. Here's the path:
https://www.lynda.com/learning-paths/Developer/become-an-ios-app-developer
Another idea is to buy this series of books:
http://www.iosappsfornonprogrammers.com
He will also probably release the iOS 10 version (and XCode 8 and Swift 3) later this year (or maybe next year), but it seems that you'll never have the most recent version, and if you want to start learning, this series certainly gives the complete newbie everything he/she needs to get a basic app up on the app store.
Finally, everyone here seems to recommend Ray Wenderlich's website (along with his instructional videos and books). Also, I've heard many successful developers interviewed who said that they STARTED with his site, and branched off from there. So, I'm now wondering if that's really the place to start with:
https://www.raywenderlich.com/category/ios
What you're trying to do...learn Swift in a day or two so you can develop an app, is actually so absurd it's almost laughable. If you're not really a computer programmer and you know nothing about how XCode works, you can be an absolute genius, and work for 24 hours a day, and I can tell you there's absolutely no way you'll have an app up on the app store in a day or two. If you do, then I want to take YOUR course when you develop it and post it online!!! Trust me...as I said, I used to be like you. I also wanted to learn this quickly and put an app up there in a MONTH OR TWO, and here I am, almost three years later. Now, I haven't really tried as hard as I should have. But I became very quickly discouraged by how much time and work was required. This would be much easier for me if I weren't 49 years old with a full time career. But if you're college-aged and floating around looking for something to do, you may have a good shot of getting through this stuff before 2017 and getting your app out there.
Oh, and one more thing. Everyone else here will tell you think of a good app idea FIRST, as that will serve as the primary motivator and driver to keep you studying and working. If you're just learning for learning's sake (like me), it will be much harder because what exactly are you going to practice programming on? Get that IDEA for the app...the rest will become much easier afterward. Good luck!!
