@Barbara Suesser-Rechberger -

Under the free plan you are permitted up to three active boards so yes, you could create separate boards for each project and share those boards only with the team members for each of those projects.

Kiron

Thank you for your answer. But if I will invited to an project, it is not possible to generate additionally an own one (in free plan mode).

@Barbara Suesser-Rechberger -

If someone invites you to their team, they would end up paying for your use of their boards assuming they are on a paid plan. You should still be able to create your own team and create boards within it.

Kiron