Hi. I think most of the clear explanation has been done by Suzie_Homemaker, but also another factor to consider is your Province in Ontario we're allowed only two babies under two y/o.
My personal experience is that parents look when their baby is about 12 months (when their mat leave is over, also in Ontario that might change our mat leave has just changed to 18 months). Many of my friends caregivers have been looking for the over two's without luck (many centres, preschool programs and new daycares in schools have been taking the over two's )
You can change your age intake but make sure to comply with your province regulations.
In regards of buying stuff, my personal suggestion is to wait until you have babies starting your program for sure. Even so, you can ask parents to bring their own playpans. High chairs take too much space try to get the travelling compact kind of buster sit ones that comes with a food tray. (Babies grow up fast your equipment will have to be storaged eventually). I usually use mine for few months then they transition to the toddler/preschool tables and cots.