If your clutch is adjusted too loose, which is to say when you pull in the lever it doesn't fully disengage, that will affect how difficult it is to engage first or neutral at a stop. Conversly, if it is too tight, you will get slippage when you accellerate or when you are using the kick starter.
I rode quite a bit in stop and go traffic here in Chicago. I found that if I didn't have the clutch set up just right, over time it would heat up and get grabby and make it hard to get into first at a stop.