Every German company is required to have its registered seat within Germany. Besides the company of course could maintain branches all over the world. Anyway the company firstly needs an address somewhere within Germany. If you for first have no premises within in Germany you need to rent an office or at least an address. Please read out the following to decide what meet your needs:
1. Virtual office (postbox)
In former times a virtual office was sufficient. Nowadays you need kind of a real office. However in some individual cases, such as if your business purpose is merely about asset management, a virtual office (meaning a postbox with a service forwarding you incoming official mails) could still be sufficient.
2. Shared office
Basically all other kinds of business purposes a company could have require a concession of the appropriate public trade office. So to receive this concession the trade office requires and will check out a rental agreement of a real existing office and not just a virtual office (postbox). Anyhow the trade office fortunately accepts renting a room ("office") in open space offices. Most important is that a person could work at a desk and that the company could be reached by calling.
Right now there are several providers of such share office solutions all over Germany. We gladly would support you finding an appropriate office solution meeting your Needs.