Let me confirm, the bike normally starts first time but if it doesn't you can't start it at all? If you left the bike for say half an hour would it then start? If yes then you are flooding the engine, two options, open full throttle and press start button for about three seconds, repeat once or twice then try starting normally, this should get loads of air through the engine and evaporate some fuel, if that fails then leave for at least 20 mins for excess fuel to evaporate If no I would suggest it could be the battery, it maybe faulty and only holding enough charge to start the bike once, if you can jump it straight away after your initial attempt I'd say this is your most likely cause. Though before replacing the battery check there isn't something draining it, lights, heated grips etc.