Some items like sherpa maps and pirate maps show up in my inventory and like capture a horse but in shop home like where you add items to your shop it does not show up.

Are they from a quest? I was told quest items aren't able to be sold when I wondered something similar ^^

Yes but I have been able to sell stuff from quests before

Yeah the items you get from quests can't be sold or transferred. If you get maps from explore or login bonus, those can be sold. Its just specifically the ones the guest lady gives you

Items listed in brackets like (3) means you own that many that are untradable.

When the new quest prizes came out you were able to sell them but Eve took away the ability to sell them shortly after. Quest prizes haven't been sellable for a while now.