for ace monsters, it depends. If your deck greatly needs 3 or 2 of your ace monsters or monsters that are like semi-ace monsters then 3 sounds fine. For me both of my main characters and side character, will have one ace monster because the deck will be mostly focused on them (not completely but mostly). 

This is going to be the character sheet

Name:
Age:
Deck theme: (could be None if you don't have a theme)
Summon Focus: (Could be multiple) XYZ Summon, Phase Shift, Fusion, etc  
Ace Monster:
Features: (The look of you character)
Information: (You could put unknown if your character is that mysterious)

But you can post them on the actual rp when it starts