Visiting www.gitlab.com redirects me to https://about.gitlab.com/. There are three big options:
1. Community edition 2. Enterprise edition 3. On our server
The 3rd option has this text: Free hosting for private repos? Sign up to get unlimited repos and collaborators.
Clicking on Sign up takes me to https://gitlab.com/users/sign_in which has clear options to sign in or sign up. It also has the text: GitLab.com offers free unlimited (private) repositories and unlimited collaborators, please sign up or in on the right.
In lesser words, it seems pretty clear-cut to me. They offer unlimited free hosting for your repos. I did not see any trial period anywhere. Maybe you went to the Enterprise option?