Terminal nao executa comandos basicos

Eu instalei o linux 18.10 e ao tentar usar o terminal, basicamente tudo me retorna isso:


Ign:1 http://br.archive.ubuntu.com/ubuntu cosmic InRelease
Ign:2 http://br.archive.ubuntu.com/ubuntu cosmic-updates InRelease
Ign:3 http://br.archive.ubuntu.com/ubuntu cosmic-backports InRelease
Err:4 http://br.archive.ubuntu.com/ubuntu cosmic Release
404 Not Found [IP: 200.236.31.4 80]
Ign:5 http://dl.google.com/linux/chrome/deb stable InRelease
Err:6 http://br.archive.ubuntu.com/ubuntu cosmic-updates Release
404 Not Found [IP: 200.236.31.4 80]
Err:7 http://br.archive.ubuntu.com/ubuntu cosmic-backports Release
404 Not Found [IP: 200.236.31.4 80]
Ign:8 http://security.ubuntu.com/ubuntu cosmic-security InRelease
Atingido:9 http://dl.google.com/linux/chrome/deb stable Release
Err:10 http://security.ubuntu.com/ubuntu cosmic-security Release
404 Not Found [IP: 91.189.88.142 80]
Lendo listas de pacotes... Pronto
E: The repository 'http://br.archive.ubuntu.com/ubuntu cosmic Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://br.archive.ubuntu.com/ubuntu cosmic-updates Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://br.archive.ubuntu.com/ubuntu cosmic-backports Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'http://security.ubuntu.com/ubuntu cosmic-security Release' no longer has a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

O 18.10 não tem mais repositórios ativos porque ele é EOL (End Of Life).

Para usar o apt no 18.10 você faz isso:

https://www.vivaolinux.com.br/dica/Como-usar-o-Ubuntu-vencido

Não sei se a dica acima ainda funciona, pois ele é de 2013.

Se eu fosse você, instalaria o 18.04 ou o beta do 20.04, que vira estável este mês.

Obrigado, fui ler depois e vi o 18.10 já não funcionava... Mudei pra 18.04, bem melhor, menos dor de cabeça....Mesmo assim obrigado pela resposta.

Faltou marcar o tópico como resolvido.