Carter’s
Talize has some great stuff, thrift store on Dixie and Dundas
They’re more spendy, but Snuggle Bugz and West Coast Kids both have a good amount of strollers and car seats for you to checkout. Otherwise would recommend Babies R Us.
For the items listed, I would also recommend West Coast Kids, Snuggle Bugz and Babies R Us
Toys R Us/Babies R Us Once Upon a Child (some second hand stuff some new, can also give them old baby stuff in good condition for store credit) Walmart has a good selection of strollers and car seats in store