CREATE ME A ROBLOX GAME

I am looking for an all in one package to create game in my Roblox Studio account or with another program. The rooms to conceptualize the game are Brookhaven, Murder Mystery 2 and Meep City. I would like my game to have a house, coffee shops, restaurants, and a trampoline park.
Please use your own creativity for this project. This is for an 8-year old little girl. Not sure if this helps!