AFAIK you can not legally discharge a firearm, or paintball gun, or air rifle, or slingshot within just about any city limits (or even some rural municipalities) without special permissions (like a business built around shooting things for example.
Using one in your home is probably not legal, and/ or exists within a 'Don't Ask Don't Tell' kind of grey-area.
I won't get into arguments about what you should and shouldn't do in your own home, because I don't want any support to be read as implied.
Here's some 'Smokey the Bear'-esque reasons why you shouldn't:
1- You live in a Condo. People who don't like guns REALLY don't like guns, and if such a person sees you transporting a gun to and from your vehicle, they can make your life hell. "What an Airsoft Gun is and is not" is not a conversation you want to have with the Board.
This is assuming that you are transporting it safely and correctly and otherwise keeping it out of sight.
2- You live in a Condo and you have that one, really bad day.
You're home on a sick day and decide to pull it out and fondle it/ your camera, but you forgot to close the blinds. 'That Nosey Neighbor' or random passer by sees you and just after you finish your KD, the 'Nice Men In Grey Jumpsuits' drop by to have a very loud chat and flashbang the cat.
You have to run out on a borderline emergency and you leave your 'AR47-UZI Assault Weapon Capable of Fully Automatic Fire from a 30 Round Clip' laying in the open, albeit in the bedroom. The neighbor upstairs left the bathtub running while they left in a similar hurry, and now two contractors and a Board Member are all over your Condo trying to figure out who gets stuck with your damages while they try to limit further damages to the suite below yours.
And so on.
3- Airsoft guns can cause a lot of damage and general mess in a confined space. Ricochets can still take eyes/ teeth out.
I'd like to encourage you to keep doing research because I'd like to see some cool high speed photography of bb stuff, and owning one can be a gateway drug to becoming a full fledged player.
I just figured I'd be Buzzkill Grandma here so you do whatever you do in a safe and thoughtful manner.