When I got my truck it had been sitting for almost 3 years without being started. The battery was dead so replaced it, put in new gas and a fuel stabilizer and it started up and ran fine. Gasoline breaks down over time and can clog flies lines and injectors.
My 98 E36 has been siting ilde my garage for 2 years currently. I'm currently in the work of fixing a few things, including the hood release cable, which is what caused me to stop driving it for a while. Prior to starting it back up I'm replacing all the coolant, changing the oil, changing the soark plugs and checking the brake fluid. One thing I noticed, ad ts dependent on where you live, but I had a ton of surface rust on my brake rotors. I have to take them to get maimed to get the rust of so make sure you check yours too.