I recommend that you place a search advertisement yourself. Last month, I conducted two purchase consultations for properties in Cologne, which had been initiated and advertised by the prospective buyers themselves, with good and quick results. Real estate agents are indeed dispensable and usually do not contribute anything substantial to the real estate transaction. The properties on real estate portals are "leftover stock"; the really interesting properties are directly mediated to clients registered by the agents. This route is, of course, also open to you; however, property owners increasingly do not want to use the services of an agent for understandable reasons and do not officially offer them. There are now also some (mostly) agent-free portals, e.g., the offerings of the large E... department store.
Foreclosures can be interesting if you are familiar with the subject matter, know how to read the expert reports, and can estimate the renovation and conversion costs in advance. Unknown construction and planning law aspects and not entirely clarified ownership conditions can turn the acquisition into a surprise package. Basically, only something for "professionals" or people with courage and a well-equipped construction budget.
In general, I recommend that, if you have concrete interest, you always take an expert (architect/civil engineer) along to the second appointment, who critically examines the condition, the renovation effort, construction and planning law issues, and already carried out "renovation measures." He should be able to roughly estimate the upcoming renovation and conversion costs and also calculate the purchase price on-site after the viewing according to the shortened material value method. This provides you as the prospective buyer with a very concrete basis for realistic financing considerations.