we have to apply for a FOID (Firearms Owner ID) card. Fill out application, send in money, wait 6-8 weeks +/- for return of card. If you don't have an ID card, or don't have it on your person, you cannot handle, purchase firearms, ammo, primers or powder. If you have an ID card, just not on your person, and get caught with a gun, you can get in trouble (depending on jurisdiction/arresting officer). After you go through this background check, each time you purchase a firearm, you go through the federal NICS check. (BTW, supposedly the State checks every FOID almost every day in the system. CC'ers get another check.) Weapons must be cased and unloaded, and, a funny one here, the local Rural King sells firearms, but they are technically within 1,000 ft of school property (across a retired RR, 2 ditches, and a treeline to the back of the large property). If you buy a gun there, you have to bring in a lockable case with lock to get the firearm out of the store to your vehicle. What you do after getting to the vehicle, well, whatever.
After your initial purpose, {*ETA: purchase} there is a three day waiting period, and recently, this includes ALL arms, not just handguns. There is a recently passed Red Flag law, so don't make any one mad at you, or you can get SWAT'ed. (Get the law called on you for no other reason than someone may not like you.) This will result in a taking of your firearms until you can prove you're innocent, a little backwards from the way I last read the Constitution. And Springfield, one of the capitols, (Chicago is the other one), is trying to pass nearly every anti-gun measure anyone has thought up in the last 10 years, it seems. Hope that gives you a little idea of what it's like to own guns in the Land of Lincoln.