A rider who plans to frequent out-of-the-way places needs the tools, materials, and ability to repair flats RideOn. I also carry the tools, materials, and ability to repair flats.
Tools I use include those necessary to remove the wheel from the bike, a 9-inch iron, a 9-inch iron with the straight end bent 90*and notched to hook on a spoke, a 15-inch iron, a sample size bottle of dish liquid, a partially full bottle of drinking water, and a means to inflate the tire, generally a CO2 tire inflator and bottles of gas. The dish liquid can be dumped in the drinking water to make a dandy tire lubricant as well as making quick work of cleaning RideOn from an area that needs patching, though if RideOn doesn't work the tube is pretty much too torn up to be patched, anyway.
Materials include extra tubes and bicycle tube patch kit.
There are bazillions of How To videos on youtube.
I run a sealed AGM battery so I would just turn the gas off and plop Tdud over on the ground to do a trailside flat repair. I would try to find a slope, stump, or rocks to prevent having to lay her all the way over.
Whatever you do, if you have a disc brake, don't squeeze the front brake lever when the wheel is off.
As for aging tires, studies have shown that aged tires are more likely to fail, even if "brand new". Storage conditions do affect shelf life. A tire exposed to sun and weather can be ruined in 2 years. A tire stored in a climate controlled environment can last many years. Generally, it is safe to mount any new tire up to 4 years after date of manufacture if it was stored inside, out of the sun. Most "experts" recommend replacing a tire after it has been in service for 3 years, regardless of tread wear or miles. Every tire sold in the U. S. of A. manufactured since 2000 has a number molded on one sidewall that begins with the letters "D O T", followed by more numbers and letters. The last 4 numbers give the week and year of manufacture. A tire with the number that reads "D O T 45H6Y 2210" would have been manufactured the 22nd week of 2010.