what needs to be done to a vehicle that is going to be sitting for a year?
Add gas stabilizer to the gas tank.
Seal opemings (like the air intake snorkle) from critters.
Many folks would suggest squirting a bit (teaspoon perhaps) of oil in the cylinders.
Change out the coolant and oil so it’s fresh.
Getting it up off the tires with jackstands.
DO NOT leave the parking brake on.
When you return, post back for advice on waking the sleeping beast. My suggestions will start with checking out the brake system.
I would add that disconnecting the battery and moving it to a different location where the temperature is more even will be good for the battery and it will make your car a little less attractive to someone wanting to steal it. As will putting it on jack stands. Nether will make a really big difference and modern tyres really don’t need to be off the ground, but it certainly will not hurt.
It would also be good to put your battery on a battery tender (not a typical charger) to keep it charged. Also remember if you have a security system on the radio, it would be good to make sure you have the code written down where you can find it.
Also check your insurance. You may be able to cancel collision (not needed if you are not driving) and save a lot on your insurance. Remember to put the insurance back on before you start driving.