Help with game mechanics

Hi. I decided to make a game without any previous experience and i’m following youtube tutorials to do the first person camera and the movement and gravity for the player but i have all in a cylinder because i don’t know anything about unity or scripts, so now I’m working in blender to create models of characters meanwhile i found help whit the game mechanics. I want to create a playable demo first of a game of a blacksmith and expand it after that. I need help with the system of interactions. I want a sleep system and a day-night cycle for that. Also i need do the minigame of forge so if you can bring me help plz answer