Creating graphics using AI to make it look like a photo

I am looking for a person who works with AI and is able to generate several photos, in several sessions according to certain parameters.

For example, a photo of a group of 30 seniors smiling and waving for a photo, in front of a building, or in a hall. The same group of people, for example, sitting at tables or as an audience. Another session, a group of children playing in the hall, on the grass, by a window, etc. It is important that we are able to modify this photo, e.g. there are 5 people, we want to increase to 10, they are eating sausages, change to buns, etc., age too young, we want to age these people, etc.

Ideally, having already a background photo (hall, building, hotel, etc) we would like to superimpose the people on it.

I look forward to suggestions and prices, as well as if you have already taken such photos then a link to them.