First off, look at the dipstick, make sure the oil level is correct. If that’s not the problem , next up, as already mentioned, there may be some problem with the air filter replacement. It’s possible to damage the mass airflow sensor if not done properly for example. More likely a vacuum hose has been left off somewhere, and the engine is leaking vacuum. that would cause poor idle performance with a cold engine. Experienced shops know how to do a complete vacuum system test to make sure the whole vacuum system is intact and not leaking, something they do all the time.
If this happened to me I’d probably just take all the air intake stuff apart from where the air comes in by the grill all the way to the throttle body input, make sure there’s nothing blocking any of the paths. Sometimes a shop will put a rag somewhere to protect the air intake from getting dirt in it while under maintenance, and forget to remove it.
Less likely, the idle air control function is not working for some reason. could have been inadvertently damaged during the other work, but not likely. More likely in that case is that there is no relationship to the previous work, coincidence. Idle air control malfunctions is a common problem reported here btw. Not only the focus, but in general.