You don't have to wear pressed trousers and V-necked woolly jumpers to play golf.
You can wear what you like though some clubs do have a dress code.
But things are becoming more modern. Check what the rules are before you play.
The only thing that really is a must is a good set of waterproofs or at least a waterproof top.
Make sure they are light and flexible enough to allow you to make a proper swing.