[kqia040]

If you have no technical background then you should start by learning a programming language such as python. If you do hav a technical background learning optimisation and machine learning has two paths. 1) theory 2) practical. Most of the time in these two fields to start off as a beginner in depth theory knowledge is not required so you can play around with some open source libraries and get started that way.

In terms of iOS and entrepreneurial ventures my opinion is that you shouldn't focus on say "iOS" as you have framed it. Startups is about finding a problem and building a product that people will use. iOS is a tool that will help you to do so. Likewise the product could be a website (so you'd use a different tool to build, such as ruby on rails) so it ultimately comes down to what you want to do. If you don't have a technical background, even to do a business role in the tech world, it won't hurt to learn one programming language as from there you will have your foot in the door.