Nearly every novice climber top-ropes first, before considering getting on the “sharp end” of the rope. For top-roping around Perth you will need a 50 or 60 metre climbing rope, a length of static rope or long slings for setting up the toprope, three or so locking carabiners, some quickdraws and bolt plates. Shoes, harness and a belay device will be helpful too. This stuff is not cheap but if you hook up with someone, you can split the cost.
Climbing shops are full of books about starting rock climbing and nearly all of them have a section on gear. When and if you start leading later, things will get more expensive: a full set of nuts, including four or five RPs and eight or so cams, including three microcams and some more quickdraws and longer slings will see you through. As for what brands to use – talk to other people at the crags, ask.