We have all been newbies at some point 
Better to admit to what you don't know that to try and bluff it. Ok, the idle up switch is an electric component attached to your carburettor which provides a bit more fuel when the engine is cold. This helps ignition. When the engine warms up, it cuts out (normally noticeable by a drop in the speed of the engine when its idling) BTW idling is the speed of the engine when no throttle is being used. If its too fast, you'll see your back wheel spinning round, when its too slow your engine will cut out. When you start your vehicle at the start of the day it will be cold. The idle up switch (or choke) assists by providing more fuel. If you aren't getting enough fuel then it won't start. You can manually provide more fuel by applying a bit of throttle when you start your scooter, but you run the risk of providing too much and flooding the engine. Over time, people generally work out how much is needed and will use the same start up process every day for their vehicle.
When a new engine is running in, it changes. As the parts wear, the engine can move more freely. This normally results in less fuel being required to get in turning over (idling), so the engine speed at idling normally increases as the running in process occurs. However atmospheric conditions can also play a factor. Its not actually liquid petrol that combusts, but petrol vapour. Cold mornings mean less petrol vapour which means less chance of quick combustion, hence more difficult to start on cold days.
So, have the days when you've been having trouble been colder? If you give a little extra throttle, does it help?