我是使用Ubuntu的新手。我正在用腻子连接和运行命令。 我具有SUDO用户权限，操作系统详细信息如下：
NAME =“ Ubuntu” VERSION =“ 18.04.3 LTS（Bionic Beaver）”
我正在尝试安装基本版，但出现以下错误：
命令：sudo apt install build-essential
Reading package lists... Done <br />
Building dependency tree <br />
Reading state information... Done <br />
Package build-essential is not available, but is referred to by another package. <br />
This may mean that the package is missing, has been obsoleted, or is only available from another source <br />
E: Package 'build-essential' has no installation candidate
我在没有sudo关键字的情况下运行了同一件事
命令：apt install build-essential ，但低于错误
E: Could not open lock file /var/lib/dpkg/lock-frontend - open (13: Permission denied) <br />
E: Unable to acquire the dpkg frontend lock (/var/lib/dpkg/lock-frontend), are you root? <br />
此后，我尝试使用以下命令更新apt-get：
命令：sudo apt-get update
结果：
Err:1 http://in.archive.ubuntu.com/ubuntu bionic InRelease 401 Authorization Required [IP: 10.15.0.115 8080] <br />
Err:2 http://in.archive.ubuntu.com/ubuntu bionic-updates InRelease
401 Authorization Required [IP: 10.15.0.115 8080] <br />
Err:3 http://in.archive.ubuntu.com/ubuntu bionic-backports InRelease
401 Authorization Required [IP: 10.15.0.115 8080] <br />
Err:4 http://archive.canonical.com/ubuntu bionic InRelease
401 Authorization Required [IP: 10.15.0.113 8080] <br />
Get:5 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB] <br />
Reading package lists... Done <br />
N: See apt-secure(8) manpage for repository creation and user configuration details. <br />
N: Updating from such a repository can't be done securely, and is therefore disabled by default. <br />
E: The repository 'http://in.archive.ubuntu.com/ubuntu bionic InRelease' is not signed. <br />
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/bionic/InRelease 401 Authorization Required [IP: 10.15.0.115 8080] <br />
N: See apt-secure(8) manpage for repository creation and user configuration details. <br />
N: Updating from such a repository can't be done securely, and is therefore disabled by default. <br />
E: The repository 'http://in.archive.ubuntu.com/ubuntu bionic-updates InRelease' is not signed. <br />
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/bionic-updates/InRelease 401 Authorization Required [IP: 10.15.0.115 8080] <br />
E: Failed to fetch http://in.archive.ubuntu.com/ubuntu/dists/bionic-backports/InRelease 401 Authorization Required [IP: 10.15.0.115 8080] <br />
E: The repository 'http://in.archive.ubuntu.com/ubuntu bionic-backports InRelease' is not signed. <br />
N: Updating from such a repository can't be done securely, and is therefore disabled by default. <br />
N: See apt-secure(8) manpage for repository creation and user configuration details. <br />
E: Failed to fetch http://archive.canonical.com/ubuntu/dists/bionic/InRelease 401 Authorization Required [IP: 10.15.0.113 8080] <br />
E: The repository 'http://archive.canonical.com/ubuntu bionic InRelease' is not signed. <br />
N: Updating from such a repository can't be done securely, and is therefore disabled by default.<br />
N: See apt-secure(8) manpage for repository creation and user configuration details.<br />
我遇到了以上授权问题。有人可以让我知道为什么我遇到此授权问题以及如何解决这些问题吗？