How would I be able to ship a bicycle on an airplane? It's a domestic US destination.

When my singlespeed MTB project is finished, it will be very easy to take apart- with the 2 tools in it's kit i should be able to take off the bars, wheels, seat, and light very easily.

But will that be enough?

First ... read this: https://www.ibike.org/encouragement/travel/bagregs.htm (Airline Baggage Regulation for Bikes)

If you are in the US and shipping within the US, you will have to box the bicycle and brace yourself to pay a fortune. Will you be travelling with the bicycle, or just shipping it?

You can usually pick up the box at a local bike shop. You take off the pedals, wheels, and handle bars. If you want to protect the tubes, covering them with pipe insulation works pretty well. Something I have done is to ship the bike to the address I am going by UPS or Fedex rather than wrestling the thing through the airport. The cost is probably less that way too. A problem with shipping though is that none of the shippers is all that careful. The box will often be beaten up and sometimes the bike will be a bit damaged also. Some people buy hard special built containers for shipping bikes. However, you can insure the bike but not the carrier (or so I have heard) and the carrier costs $$$.