Somber stones items that have levels you will see the level in brackets [] Example Somber Stone [2], this means that is used to upgrade an armament that is already a +1. Most surely you don't have the Somber Stone in the level that is required on your armament at the moment.

Might need more runes

Don't have enough runes

learn and try, die and die again until u get better. The harder the enemy the faster u learn.

eat mushroom to grow your mario then save the princess, watch out for bowser he's a bastard