Hi Christopher,
Do you know your new tenant name and/or tenant id? One or both may be in the welcome email you received. Please look in the email(s) for tenant id, any GUIDs, something ending in .onmicrosoft.com, directory name/id, etc.
For example, if you signed up using Microsoft account tied to ******@gmail.com the tenant name might be youraddressgmail.onmicrosoft.com and the tenant id would be a GUID (e.g. 84ada73c-c1a6-49d3-83d8-7a270e1a473b). You would've seen the name during the signup process if I remember correctly.
Note your old, blocked tenant might already be named youraddressgmail.onmicrosoft.com so your new tenant name would be different.
Once you know your tenant name or id, open a Guest profile (in Chrome, click little person icon in upper right corner -- Open Guest profile) and then navigate to the portal with the name/id appended, similar to below:
https://portal.azure.com/youraddressgmail.onmicrosoft.com
https://portal.azure.com/84ada73c-c1a6-49d3-83d8-7a270e1a473b
Sign in using the Microsoft account you used to create the free trial.
Please click Accept Answer and upvote if the above was helpful.
Thanks.
-TP