tanks are plastic, no need to fill it. when tanks were metal, the air pocket above would allow humidity and condensation to build up and start rust. hence the whole fill the tank advice, but it's dated.
disconnect battery for sure or put on trickle charger. why you storing it anyways? and why inside?
do not put the car on jack stands. a drooped suspension will fail when you put it back on the ground after a long time. ask how i know.
inflate tires to 40 psi and put down squares of styrofoam (like from a TV box, or other electronics) under each tire. those interlocking squares for kid's playrooms are too soft, i find styrofoam has the perfect 'give' for storing cars. you can buy it from home depot too if you don't have any at home. failing that, you can stack like 15 disposable styrofoam plates from the dollar store too under each tire.