Jacking the car up to "relax the springs" doesn't do anything for the springs, but it puts severe torsional loads on the control arm bushings they weren't designed to carry for extended periods; just leave it at normal design ride height (jackstands under the control arms) if you want it up off the floor.
The last thing you want to do is to start the engine while the car is being stored - the cold-start rich mixture byproducts and condensate go right into the crankcase, the oil doesn't get hot enough to boil them off, and those contaminants make the oil more acidic, which creates sludge. Unless you can get the car out and drive it for at least ten miles, just leave it alone and start it in the spring; the seals won't dry out - that's an old wives' tale.
I've been garage-storing my toys through Michigan winters for over 40 years, by filling the gas tank, add some air to the tires, close the windows, and put a Battery Tender on them occasionally. Rodents and humidity (corrosion) are winter enemies - focus on those issues. When Spring comes, check the tire pressures, start it, and drive it.