If your shooting small items especially to sell. A light box is your best friend.
https://www.bhphotovideo.com/c/searc...rch=yes&sts=ps
IMO you will have to have a Micro lens like my Nikon AF-S Micro NIKKOR 40mm F2.8G. Yes you can spend a bunch of money on a lens but for your first one keep it simple and not $$$$.
I mentioned before the editing software. Skill with editing program will fix a multiple of evils. Here is a picture from our site as an example. Light box + NIKKOR 40mm + Pixelmator Pro. These are a nightmare to shot as they are only 5mm in diameter and cast a ton of shadows.