An L plater you may be but at least you have the sense to ask for help.

I am not a seller so I think I will leave it to those with more experience of postage to answer.  But I do know that if the items will fit in a flat rate satchel that will be your most cost effective postage Australia wide.  Overseas postage is going to be expensive, but it is just as bad for items coming into Australia so don't let it put you off.

Another poster has mentioned your low feedback.....it is also rather old.  You could give it a bit of a boost by buying a few cheap items.  It makes you look as though you have some current ebay experience.   Try a few $1 items from China...the Chinese sellers usually give feedback as soon as you pay so you could see an instant increase in your feedback for a very small outlay.