Kmart and Bunnings are your go-tos for most things. Target and Big W are good too for the things Kmart would have. Kmart particularly is good for quick cheap stuff. Bunnings is mostly trady stuff, but you can also get a lot of home electronics like powerboards (I particularly like my outlet tower with 3 USB-A ports and one USB-C).
For electronics where quality matters a bit more (particularly your kitchen stuff), JB Hifi or Good Guys.
(Note: if you're American, our Kmart and Target are effectively entirely unrelated from yours.)