How and where to look for performers for the project?

At the moment, the task is to find a company that would help create a presentation for the project. In the past, there were tasks in finding a partner for site design. In the future, there will be questions about where to find an advertising agency, etc., etc. ...

Are there projects in the network where you can find professional performers for your tasks? Where it would be possible to discuss this or that regular work, get advice, recommendations, compare one company with another.

The question is on professional teams. I understand that among the freelancers there are geniuses and I will never oppose cooperation in such a format, but it is the discussion of companies that interests me.