You may be better sticking them on eBay, you’ll get a bigger audience and probably more money. You select which postage method you want to offer, Royal Mail, Evri and I think another courier. Buy pays postage and eBay send you a postage label for you to print at home or a 2D barcode to take to the post office or Evri drop off point, they’ll scan the code and print your label for you. All you need to do is find a box and package them up. I ran a business selling on eBay for over 20 years, it’s really easy now.
And it is now one of the most expensive places to sell anything as a business seller. Put the items for sale on Gumtree it’s free for the advert and no fees to pay.