upgrading melee weapons (in New players)

does anyone know which melee weapons are upgradable or how to tell which ones are?

All melee weapons are upgradable. Some are only possible to upgrade through blacksmith, other only for forging, and many are able to upgrade through both.

Most melee weapons with a base damage (the number before the x) of lower than 50 are not worth upgrading much, you'll soon be able to buy better ones.

All items are upgradable, however it is generally a waste of money to upgrade a non-rare of any type.