I've never had the iFlight stack, but most pads on these electronics seem small at first. The cool thing about a stack is that you don't have to solder the motor wires or solder the wires to power the flight controller.

I recommend you get the proper tools. Like some Solder Wick, A practice soldering board, and a good soldering iron. And finally, a smoke stopper will prevent you from frying your electronics if you mess up soldering.

To limit the amount of times you're going to crash, you should probably get a flight sim to get your handle on the controls.

And of course, post here for anything you need. Make sure to include pictures that shows everything you've done.