I went on a day scuba diving trip to the great barrier reef at the start of the year and loved it! But Im putting off doing my certification because i know i wont be able to buy my own equipment untill i finish uni. My question is do many people scuba dive regularly with borrowed equipment, or is it really nessery to own your own gear??

It’s a matter of preference and economics. As a general rule of thumb though you definitely want to buy your own regulator, mask, fins and snorkel. You might also want to consider buying your own wetsuit as well if you’ll be diving in cooler waters.