Bought a new battery and my bike still won't turn over

alternator has nothing to do with engine turning over, unless it froze.

Usually if you flood it (by overchoking), you open the throttle wide open (to draw in more air to lean the mixture) while cranking starter.
Beings you had the spark plugs out you could have cranked it then, and let the engine compression blow the excess gas out the spark plug holes.

sounds like a bad earth if you have jump leads go direct of earth to engine to see if this cures it if so you no where problem is clean replace earth

It sounds like it may not be getting enough fuel to the carb(s). Check to make sure that fuel is flowing from the tank. If not, it may be a problem with the petcock or the vents on the gas cap may be clogged.

leave it sitting for a couple of days and it should start fine. ;-)