You may find that you have total clutch failure! Either your cable snapped, or there is a major leak in your hydraulically-operated clutch line if you have one, or some other reason. Don't panic, you can get the bike home. I have done it a couple times through rush hour in DC so it can be done.
The biggest challenge is getting the bike rolling. Obviously with the engine off, you can easily click through the gears, so you can start it in neutral. But without the clutch you will immediately stall out when you shift to 1st gear. There are two ways to get started. First, you can put the bike in 1st, and then hit the starter button. The bike will lurch forward, and if you have a good battery, it should get you going fast enough so that the engine can catch and engage. The second method is to start it in neutral, then get rolling slowly down a hill. Put gentle pressure down on the shift lever, and once you hit about 5mph, it will slide into 1st gear.
So now you are rolling in 1st gear, how to shift? Well, rev the bike up as normal, as if you were riding it with a functioning clutch. When it is time to shift into 2nd, let off on the throttle, and put gentle pressure up on the lever. The engine speed needs to fall to the spot in the gearing where it can easily slide into 2nd. Don't pull up hard on the shift lever with your foot or you may have a hard shift and possibly do some damage, just take it easy. Downshifting is done the same way, but you may have to flutter the throttle a little bit to find that "sweet spot." It is different on different bikes, I can't tell you at what RPMs and road speed each shift point is, you just gotta find it. This is a good skill to practice before your bike breaks down.
You will find that you have a hard time stopping! If you come to a light, you will either stall out, or get into neutral and then can't get going again. If this is the case, you will need to do your starting procedure all over again. Therefore I suggest plotting out a route home that includes all right turns, and doing as many stop sign "stoptionals" as you can. No cop, no stop!!! Just do what you gotta do to get yourself home and repair the problem properly.