You can upgrade your shield and weapon(s) at the blacksmith. There is a blacksmith in the nexus who does basic upgrades, as well as a blacksmith in the start of 2-1 who does more advanced ones. Don't worry too much about armour.
Spoiler: There is a crescent falcion in 4-1 that will be VERY useful since you are a royal. You get a damage bonus based on your magic level with it.
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