im thinking of taking up scuba diving if i like it, but there are different wetsuits, fins etc, how would i know which to buy? is there a way of getting them cheaper also? thks

The absolute bare minimum you’ll need is mask, fins and snorkel. You’ll need all that day one of your course. You’ll also need to make sure they fit. Only one way to do that and that’s not by buying online. You need to go into a dive shop.
Cheaper? Then forget scuba. It’s not for people that skimp on their gear since that gear is what keeps them alive. Even simple things like mask, snorkel and fins that don’t properly fit or are cheaply made can get you into some serious difficulty.
If you bought an entire package from a dive shop, they’ll probably give you a discount ( normally whatever the sales taxes are).