You need to have low/medium/high quality food in your inventory. Each person in your villa (you, Livia, servants, tutors, bulls...) eats 2 food items every day (if they haven't eaten day before, it's more). This can grow up very fast, if you don't have a good food management and you bring a lot of people in. You need to upgrade your kitchen, to cook food faster. Always have household servant or Cornelia to cook food for you. You can have farms to grow food, instead of buying it. The food is basically a limiter to how many people you can support in your house. It is a management game, after all.
Early game strategy is to have 1-2 servants in training (optimally one that can help with food, like household or farm servant) and develop farms as soon as possible. Later game strategy is to have 4-6 farms, farm servant to work on them, cook to cook food and other 2-3 servants in training with tutors.
Also, you need to raise in ranks, before bringing more people in. You cannot support a large household as a scribe. You need to be at least a quaestor.