That depends on what you call "shooting". There are so many different facets to the shooting sports and air guns have equivalents to all of them! Everything from backyard plinking, target shooting, and hunting to ISSF 10 meter and extreme benchrest.
I'll assume that you're talking about pellet rifles and not BB guns. Also, that you're not quite ready for the expense of PCP guns and all of their associated accoutrements. That leaves CO2 and piston powered guns, as they will be more-or-less self contained to allow you to just grab the gun and pellets while heading out the door.
Since you said it's for just starting out, I think we can eliminate high-end guns and competitions, too. Realistically, any gun can be used for shooting cans and bottle caps. What really matters in every type of shooting is accuracy. As Wyatt Earp famously said, "Speed is fine, but accuracy is final."
With all of that in mind, let's continue. I don't know what your budget is for this endeavor. So, I'll just give you a couple of ideas that aren't too very expensive but should be good starter guns for you:
$60 Crosman M4-177 - this is a pump-up rifle and accurate to about 10 yards. I shoot backyard mice with it from my kitchen.
$130 Krale Artemis CP2 - a fun little CO2 pellet gun in .177 or .22 with about 12 FPE (ft/lbs) good for close rattting.
$190 Crosman Mag-fire Mission - a multi-shot break barrel in .177 or .22 with about 14 ft/lbs of energy for rats/pigeons.
$270 Benjamin Trail Nitro Piston 2 Elite - a durable and field-worthy companion for hunting with 16 FPE.
Others will have their favorites, such as Beeman, RWS, Diana, Hatsan, etc. and you can't go wrong with those brands.
Let us all know what you decide to get, how you're using it, and (after some time shooting it) whether it's "The One" for you. We have all been bitten pretty hard by this bug and are curious about what might be the next pony in our corral.
Good luck,
~ Mondo