If you want to target the Apple iOS devices only, then you will have to download Xcode development tools,
from the App Store, they are free to download, but are a big package, about 1.8gb.
https://developer.apple.com/technologies/tools/
If you want to target other mobile devices, eg. Android powered phones and tablets, then you will have to
look at tools like QT, or Eclipse, or Corona.
Qt
Eclipse - The Eclipse Foundation open source community website.
Develop Cross Platform Mobile Apps and Games | Corona Labs
Which ever devices, and required development tools you want, there will be a fair amount of coding involved, for iOS you will need to be comfortable writing Objective-C code, and for the Android powered devices you will need to learn either Java, C++, or Lua if you use Corona, out of all of the above, Corona is
probably the easiest to learn, but not the most powerful.
If you give us more information about the type of project you are considering, and your level of Programming experience, we could offer more specific advise.
Regards Mark