I'm sure you've got this figured out by now, given that it's a month and a half later, but assuming you're talking about cerevisiae, their optimal growth temp is 30 degrees celcius (whatever that is in fahrenheit), but as everyone who brews ales knows, they'll grow fine at room temp. Store your plates in the fridge, wrapped in saran wrap or something to prevent dessication (and contamination). Parafilm is optimal.
FWIW, my PhD was in yeast genetics.
Good luck!
Todd