I am happy to help out where I can. There are plenty of VERY experienced sellers here with way more experience than me, who would also be willing to impart their knowledge too. Ask any questions you like and there will be quite a few willing to help you out and steer you in the right path. We all made mistakes in the early days, so it's great that you can hopefully bypass some of them by asking for help early in the peace.

I think there would be quite a few new sellers who end up giving up because they follow eBay's advice, which for most things is to start auctions at 99c (to attract more buyers) and they discover they are actually in the red rather than making money. The reality is, once upon a time that did work and for a few sellers, it still does (it really depends on the item), but for most others, items sell with just one bid. Therefore, you always should start auctions at the lowest you are willing to accept and assume you will only get one bid.

When setting your price, always add a bit extra to cover eBay and PayPal's fees. It's 9.9% for eBay (including shipping, which you get charged fees on too) and I *think* it's 2.4% for PayPal, plus a non refundable 30c. If you want to offer "free" shipping, then you build the cost of postage into your price. It makes no difference if you offer free or costed, the fees are still the same. For a small parcel, which is an item under 500g and more than 20mm thick, I charge $8.25 when the actual postage cost is $7.45. It doesn't seem to bother buyers paying the bit extra as my postage stars have always remained at 5.

I strongly recommend investing in a cheap set of digital kitchen scales if you don't already have them. That way if you're not sure if something is going to go over 500g once packaged, you can pop them on the scales and check. You can then work out the postage cost using the Aust Post postage calculator (before you list the item). https://auspost.com.au/parcels-mail/calculate-postage-delivery-times/#/

As I said, ask away. Plenty of people here to help. That's why we're here.

Edited to fix typos and grammatical errors.