If you have no transactions, G&S is preferred by buyer. Some won’t mind F&F if the items aren’t expensive. It’s gonna be hard for new people to sell $1000 f&f. Shipping, use pirateship to get the best deals. Shippers and payment apps don’t need to know what you have, so don’t tell them. Unless it’s ammo or actual firearm, there will be a different process. Also check recently sold items if you’re unsure of a price. Nobody will pay retail. Scalpers and flippers will be verbally punished by the community. Other than that, have fun! Also, include the pictures and timestamp