How do I create several business entities under ONE single business name?

If you have the capital then go ahead and incorporate your company if not register as a small business if you don't have the capital to cover incorporation. But once you have a name then you can just use the name on your different ventures e.g ABC / ABC dance / ABC model troupe or if u want to feel safe register all the main business and all the separate business carrying the similar names and use one bank account. U can incoporate all the businessess under one LLC when u have made enough money.