The laziest way to fix your issue is to chmod the shared directory to 777.

I would only suggest this if this is on a LAN and you are the only person using the different machines.

Pi-Hole, Nextcloud, local storage and email are used constantly. All bring great improvements.

Ansible and Zabbix provide ‘support’ for these applications.

Media streaming is a ‘nice to have’ but not essential. Wireguard is seldom used but still very important.

Do some reading up on Immich. It might be suitable for your needs.