BACKSTORY: So I'm wanting to make myself a homebrew system to better deal with how to reward experience points to my players for roleplay, spellcasting, and combat respectively rather than just the 1 experience bar that gives limited rewards as you level. I want to create a better system where the results of my players actions are better reflected than a basic standard number. Which jogged my memory of wild animals which is why I'm asking todays question

ACTUAL QUESTION: What are the stages between a hostile animal and a tame animal. What are the requirements to go from each stage to the next. Animal Handling checks? Hours of time and 50gp of food? What are they because I know somewhere there are official guidelines for this, but I just cant find it. Are there similar rules for NPC's as well that have sentience?

I would prefer references to the PHB MM or DMG but its not needed for a response.