What happens when my trial ends?
Your account and data remain intact.
Paid-plan features will be revoked thus if you anything exceeding the Free quota will be deactivated (e.g. only 10 alerts will remain active, etc). Especially for storage, you will be prompted to remove files yourself so that you will be within the Free quota of 300MB. You can move to a paid-plan subscription to re-activate your quota-exceeded features.
You can upgrade to a paid-plan subscription at any time during your trial period. In this case, you will not lose any remaining trial days since your paid-plan subscription will be initiated at the expiration of your trial.