I still do not understand how freelance works.

When you sign up on a freelancing platform, you need to select whether you are a client or a creator. I suppose you want to become a service provider, so on your account, you have to indicate the areas you do best, your work experience, and many other details that should convince a client that you offer the best freelance services on the market (https://wono.io). After a client posts a project, you have to apply for it. Then, you will have to give details about the steps you will take to do your job, the time you will perform the tasks, and the payment you require.

When you sign up on a freelancing platform, you need to select whether you are a client or a creator.

I think that the freelance 3d projects is two-way road :), but I only see " I need" and "I'm looking for..."
If on the contrary, I wish to offer my services? Is it real in these projects?

A person post a job offer demanding something to be done. As a creator, you have to apply for the job and, if you are selected for doing it, start working on it. In your application, try to prove your skills with images of similar jobs or models you have done and explain how you plan to do the job.