During the trial, you have access to most of the features included in the Pro subscription. See this link for a breakdown of all the plans.
After the initial 14 days, an additional 14 days is provided to allow access to the account. During this 14 day grace period, the site will remain online and editable. However, it will not be possible to upload new photos or videos during the 14 day grace period.
If you do not become a member within 28 days after the trial begins, the account and all of the photos will be permanently deleted.
To keep your user name, account settings, as well as the photographs and videos uploaded, please become a member before the end of that grace period.
You can become a member by clicking on the Alert icon in the top of the Dashboard then clicking on Become a Member in the box that appears.
You can also become a member by clicking on My Zenfolio then clicking on Become a Member.