Disk space critically low

I got this:

Disk space critically low

along with some other text saying that old terminal [something] would be deleted if needed to clear up space.

What is this and how can I resolve this issue?

I checked my storage and I have about 50gb left…

DreamProxies - Cheapest USA Elite Private Proxies 100 Private Proxies 200 Private Proxies 400 Private Proxies 1000 Private Proxies 2000 Private Proxies ExtraProxies.com - Buy Cheap Private Proxies Buy 50 Private Proxies Buy 100 Private Proxies Buy 200 Private Proxies Buy 500 Private Proxies Buy 1000 Private Proxies Buy 2000 Private Proxies ProxiesLive Proxies-free.com New Proxy Lists Every Day Proxies123