Learn Java, develop for Android.
Android is the low-threshold mobile environment, where you can get started with $25 and pretty much any PC hardware you can think of.
If you want to develop for IOS, you need a Mac. Case closed. If you do not have one, and don't want to invest in one, then there's no point in even getting started on IOS development.
Check out Unity 3D
This right here.
You said you were using visual studio, right ?
Unity3D supports writting code in C# as well as JavaScript. It has really strong multiplatform capabilities so you don't really need to go all native on the project. You mignt need to do some native coding to implement an in-game shop or some other kind of on-device integration, however that's going to be fairly little work and it's something that's going to pop up at the end of your development process.
