No worries.
At least you have a petrol lol, diesels take forever to get warm. My neighbour has a Dacia Duster with a diesel engine, his car isn’t blowing proper hot after 10 miles of driving.
As i said, leave heating/blowers off, start the car and have it idle for a few minutes, until there’s some heat in the engine – then it should blow hot. It goes quicker when driving of course, since you put load on the engine, leading to it heating up faster.
We usually don’t bother preheating the car, unless we take our animals to the vets. If a vet trip is on order, i’ll be outside 5 minutes prior to leaving and have the car idle (with heated seat on – heated seats are electrically heated, not through the engine cooling circuit), after 5ish minutes the cabin is cozy.
On the technical side, it’s simple. Coolant runs through your engine, from there to the radiator, and from there through the heater core. The heater core is just a heat exchanger, really. For the heating to get warm/hot, the coolant has to be heated by the engine first. There really isn’t anything you can do to speed that up other than putting load on the engine (driving), or revving it in idle up and down, though obviously revving a cold engine isn’t healthy for it either.