When running docker compose up I get "Docker socket is not readable by the www-data user. Cannot continue"

Hello @ashrite, welcome to the Nextcloud community! :handshake:

Likely you did something wrong here

would be interesting to understand where/from which folder you run this command. is /var/run/docker.sock the only file you changed the permission? why - if there is misleading instructions in the docs would be great to point them out

which files and folder? please provide ls -al output of /mnt/docker-aio-config and / var/run/docker.sock

As rookie I recommend starting here (and all 101 articles for deeper understanding)

AiO as a Docker-based installation stores it’s data in few pre-defined locations it should be easy to extract it there to start from scratch..