New Owner can you help with some questions?

[m4a1mustang]

No need to let the car sit, you just want to take it easy (i.e. shift at low RPMs, don't use lots of throttle) until the car warms up (~180 oil temp).

The car comes with summer compound tires. It can be unsafe to drive them in cold temps, even on dry surfaces. They firm up in cold weather and lose almost all of their grip which can make the car dangerous to drive, especially before the tires have warmed up (and even then they won't have the grip they normally would in warmer weather).

If you plan to drive it in the winter (even if you don't drive in snow) it's a good idea to swap to tires that are designed to perform in cold temperatures. You don't HAVE to, but it's a good idea.