[RMXP] I NEED HELP WITH THINGS

Hello. I want to make an odd rpg but I'm not sure how to do it. And it will be my 2nd game since my first game is a pkm fangame.... That I don't know if I'll post on here or not.

Things I need to learn how to do:
-Player collects items from the wild or battle.
-Player uses the items to do alchemy and cooking.
-make weapons and armors. (by using the Blacksmith)
-build buildings for NPCs
-Build and design their own house/office/workshop.
-Pets and NPCs as team members.

The games that I'm using for ref, are:
Mana Khemia - The Alchemy, cooking, weapons and armor
Final Fantasy - Battle system, Magic system
Rune Factory 4 - Story idea became from this game
Star Ocean 4 - A few items from it.