on title screen, hold the A button and press start. now you will be on 1-1!
you can also get the program SMB Fix to fix this (and other issues) too
the reason this happens was explained in this thread. the rom was dumped from a multicart. the multicart let you choose what world to start on. when it was dumped, that feature was removed. but since the would data was never set, it's up to the spot in ram to decide the world you start on. old emulators would set ram on start to 0x00. which is 1-1. newer emulators set ram to 0xff (like the nes) which is why it starts on 0-1. in the early 2000s when emulators werent as good, the rom worked fine and got spread around a lot. idiot