I have not enough experience with iOS/Android development to know, but I wonder if it isn't somewhat more easier to learn iOS for instance since it's just one language and IDE you have to focus on, while for web-dev you need to learn multiple languages. (Though at a certain point you'll need a server-side language to give your app the ability to communicate with a server...)
> If you're starting from scratch, learn HTML and CSS and make some simple static pages. Then once you're comfortable, learn a high level language (eg. Ruby or Python). Then learn a web framework for that language (Rails if you're focusing on Ruby, Django if Python). You'll probably want to pick up some Javascript too.
Exactly what I was thinking, but you gave actually steps.
Web development has many layers to it, but each layer is pretty straightforward and it all starts and ends with producing a text string (the web page) which is a much easier concept to get your head around when you're first learning.
2. Macs are popular for iOS, Android and web development so they're a good choice.
3. It's possible but it will be a lot of work. I don't have any recommendations on beginner courses. Maybe check out reddit.com/r/learnprogramming
4. As you implement your MVP, try to break each problem you face into smaller, manageable chunks. It's much easier to solve several easy - medium difficulty problems than 1-2 hard ones.