How do I solve the problem of not always having to change the address of my company headquarters if I want to stay mobile, the company only consists of an office / office for property management, consists only of folders and a notebook.
You can register a PO box for the postal address
As a trader you have a summons address. This is the address to which the tax office will send you your tax assessments.
Even travel businesses (you are not a real estate seller) have a summons address that is not a PO box.
I would register the company properly at the place of residence. You can send the post to a postal service such as Send https://getcaya.com. Do you need a summonable address e.g. A pure postal service is not suitable for the imprint of your website. In that case you would have to go to address providers such as https://anschrift.net fall back.
These providers scan your mail and make it available to you online for retrieval. Ideal for mobile entrepreneurs.