You aren't driving a sports car, doing lame cheap upgrades on a 2019 vehicle (Mazda 3 none the less) would most likely void your warranty, make it less reliable, and shorten its life. Not to mention the upgrades would have little to no effect on performance.
Cold air intake would probably make your car run worse not better and throw a CEL unless you properly reconfigure the ECU. Upgrading the air filter to a better quality one that also allows more air flow would make the engine breath a little better, but the difference will be minimal.
Are you looking for performance upgrades? or just upgrades overall.... You could upgrade the stereo, speakers, brake pads, drilled/slotted rotors, dual piston callipers, short shifter kit (if they sell those and you drive a manual - not sure if that voids warranty).
Could consider upgrading the suspension but that wouldn't be so cheap and anything you get on a budget would probably be worse than oem anyways.