u/Ferrari-murakami

I inherited a 2016 435i from my mom that has been sitting in a garage and never ran for about 1.5 years. My mom left to live in her home country after my dad passed away and doesn't know what to do with her retirement car. I said i'll keep it and maintain if she ever returns. The battery is totally shot and does not start. I will be getting a brand new battery and bimmerlink to register the vehicles new battery. Other than the battery I do have a couple of questions before I attempt to start the car:

• We did not put in any fuel stabilizer so the gas is probably old. Can I just top off the vehicle to introduce new fuel into the system?
• Since this is a BMW my concern is the oil has probably settled at the bottom of the pan due to gravity. I've read multiple forums the vehicle's engine must be primed before attempting to start. What would be the easiest less intrusive way to do this (I've broken a lot of plastic parts, so the less things I have to unhook the better)? I've read I can just unplug the DME and crank the engine 10 seconds 3 times with breaks in between.
• The vehicle has been sitting in a garage that can either be sweltering hot or freezing cold.

Thank you