You didn't say where you were attempting to download the Cloudera Quickstart from or what site was denying your access, or what version you were attempting to access. May I ask why you were attempting to download a Cloudera Quickstart? Is this a classroom assignment?
As a general matter, Cloudera is no longer updating or making the Cloudera Quickstart VM available for download (and hasn't since March of 2020) because it was outdated and obsolete as it was based on CDH 5.13, which went out of support in the Fall of 2020.
I'm curious as to why anyone would ask you to download a Cloudera Quickstart VM at this point in time, or why you are interested in a data platform distribution which does not include the up-to-date releases of the various Hadoop ecosystem components. Cloudera's current distribution, since the Fall of 2020, is Cloudera Data Platform (or CDP); a Trial Version of CDP Private Cloud Base Edition of Cloudera Data Platform can easily be downloaded and installed from the "downloads" section of Cloudera's website.