Help with setting up a shop on shopify and printful

I am a graphic designer who is already selling posters which I have designed on Etsy.
I would like to have another separate selling platform - Shopify.
I have tried to set up my shop but am struggling to work out how to do it. I want to be able to do it myself so need someone who can teach me not do it for me.
I was wanting to pay someone for a one to one, a day maximum, video call, giving me instructions on how to list products, edit and crop them, do the shop banner and advise me on marketing. Basically to take me through it, whilst doing it, so that I can continue afterwards to confidently add products to my shop.
I attach a screenshot of my etsy shop which is posters, although on Shopify I would like to do posters and t shirts.