I wanna start shiny hunting in Pokemon Y, so I read up on some things and saw that I needed to get all 720 Pokemon to get the Shiny Charm. I have neither the time or the games to do it, so for shiny hunting can I just go without the Shiny Charm or should I just not try?
It will improve your chances at obtaining a shiny by a lot, however Shiny Hunting is still possible without it, using simple methods such as chain fishing, Friend Safari, Masuda Method breeding, or, if you're really determined, just walking around in tall grass. The Masuda Method breeding is probably your best bet here, as it is both easy to learn and carry out.
Masuda Method: http://bulbapedia.bulbagarden.net/wiki/Masuda_method
More information about Shiny Pokemon: http://bulbapedia.bulbagarden.net/wiki/Shiny_Pokémon
It certainly isn't a must have, however, you'd need to be super determined if you're going to RE for Shinies without any way of boosting your chances.