Skip the shotgun shells to start with. Factory shells are too cheap to save significant money right now, and shotgun shells have a different set of problems. Keep it in mind for when shells go up and the price of shot goes down.
The 9mm and .223 are worth loading for, but not by a lot. They are about the cheapest centerfire ammo going. If you are shooting a bolt action .223, you should be able to save money while still improving accuracy.
It's still worth learning to reload, but the real savings come when you add more guns. There are huge savings if you shoot oddball stuff. Those guns mostly come cheaper, too. There are even bigger savings to be had if you get into casting. I shoot a fair amount of .41 Mag with my own cast bullets at about a tenth of the cost of factory, less than $2 a box versus about $20.