You'll need a mac to build the game on an ipad / iOS device, but starting with a PC as the platform is the way to go to. The point and click nature lends itself well to the ipad. I've made two games for iOS using Unity and javascript/unityscript and now use Obj-c and c# in my real job.
There are a lot of things to consider when choosing what platform to make a game for. UI - how will the player interact with your game, kb/mouse, touch, controller, something else... Game design - Is your game meant for longer play sessions or shorter ones. The smaller the screen + more portable the device = typically…