Thanks for playing Queen! But the Jam version with map and finished story is now available, sorry for uploading that test demo first.
Sorry for the language in the game (by the way, the patch comes out in English in July) but you can equip weapons and potions in the Equipment Menu (e.g. in weapons there are 2 boxes, if you press one you can automatically search only for weapons that you have taken (or only shields, accessories, head armor, chest, tools (potions) etc. each in its type).