Attempting To Start A 2018 Hyundai Elantra Parked Indoors For Over 3 Years

In 2018, I purchased a 2018 Hyundai Elantra for my mom. In 2022, she was no longer able to drive and it's been parked indoors for over 3 years. Sold my 2017 Mazda 6 a few months ago, so I'm going to try to get the Elantra with 7000 miles up and running.

Here's a list of what I have so far      

• A 4000A  and 2000A Peak amp 12V Lithium Portable Jumpers
• CRC05671 Starting Fluid with Lubricity (it's all they had in stock)
•  1L of 50/50 ATF/Acetone mix to spray into cylinder heads
• Siphoning hose to remove 1/8 of a tank of old gas
• 5L Jerry can of fresh regular gas
• WD40 and wire brush to clean spark plugs

What are the chances I need to turn the engine over by hand?

Would using premium gas or adding fuel additive help if I can't remove the old gas?