Unzip from Google Cloud terminal: permission denied

I’m not able to unzip the train and test files from a Kaggle dataset. The data was downloaded to Google Cloud with ‘wget’ and resides in the data folder. Currently it contains train.zip, test.zip and the folders train and test.
When I type ls, the mentioned files all show up (train.zip and test.zip are formatted in red).

I want to extract the content in the following way:
unzip train.zip -d train

This returns the following error(s):
error: cannot open zipfile [ train.zip ]
Permission denied
unzip: cannot find or open train.zip, train.zip.zip or train.zip.ZIP.

I ran the code through an ssh connection from home.
Any suggestions? Thanks

Change the user permission with chmod u+rwx train.zip helped. It also changes the font of the zip file to green.
For practical purposes: why was the access denied initially? Do I need to change any settings within the Google Cloud terminal environment? I don’t expect to run these permission commands for every file I want to use.