Welcome along AustGarageSales
Clothing is actually a pretty good choice for a first item to sell - but it does depend on what type of clothing it is. Vintage, chain store, department store, and designer items tend to sell best.
May I ask what you tried selling?
When you sell clothing it's really important you have some great photos and use a mannequin if you can, as people like to be able to see what the clothing looks like on a form, so they can more easily imagine wearing it themselves.
You also need to make sure your description contains all the essential sizing and color details so people can check whether it fits.
Apart from clothing, just selling a few things from around the house is a really good way to ease yourself into the online selling process, and see what things you enjoy selling :)