It takes a bit of practice before you can shift smoothly. It's easier on some bikes than others.
Do you have a tach? Look at it and decide where to shift. Usually you go up to something like 80% of the redline. But even if you don't have a tach you can hear where the engine sounds happiest. If it's -screaming- and it sounds like it's beating its little heart out, shift up. If it's lugging (you can feel that), shift down.
Usually you use 1st gear just for starting out. As soon as you are rolling you can shift up to 2nd. You might go back to 1st to drive around a parking lot at 5 mph, or if you're going up a really steep hill.
1st and 2nd gear have very narrow speed ranges. I mean, if you go up through the gears you might find you use 5th gear for anything over 30 mph. But 1st gear will be used up by, say, 10 mph. It has to do with the ratios. So 1t and 2nd are a little harder to use, to keep the RPMs in their proper range. But this is something else that will come with practice. The more you ride the bike, the better you'll get at it.
