Hi Lilly,
There is merit in what Wiery says, however, if you have a lesson or two you will get going quicker.
The videos will teach you the basics but won't correct you if you head in the wrong direction.
If you are going to watch vids look for Dave Kalama in particular.
There are SUP schools at Noosa, Maroochydore and Caloundra on the Sunshine Coast.
I think Briskites at Scarborough does SUP lessons too.
Yes there is such a thing as an accredited SUP instructor.
You will generally find that most experienced paddlers will be happy to give you a few tips if you ask. We are a friendly lot.
Have fun.
ET.