I can't install applications on linux (CrunchBang++) what should I do?

Question

linux

/etc/apt/sources.list

# 

# deb cdrom:[Debian GNU/Linux 10 _Buster_ - Official Snapshot amd64 LIVE/INSTAL$

deb cdrom:[Debian GNU/Linux 10 _Buster_ - Official Snapshot amd64 LIVE/INSTALL $

# Line commented out by installer because it failed to verify:
#deb http://security.debian.org/debian-security buster/updates main contrib non$
# Line commented out by installer because it failed to verify:
#deb-src http://security.debian.org/debian-security buster/updates main contrib$

deb https://debian.csail.mit.edu/debian release-code-main main contrib

and here is the error

Ign:1 cdrom://[Debian GNU/Linux 10 _Buster_ - Official Snapshot amd64 LIVE/INSTALL Binary 20190712-12:32] buster InRelease
Err:2 cdrom://[Debian GNU/Linux 10 _Buster_ - Official Snapshot amd64 LIVE/INSTALL Binary 20190712-12:32] buster Release
  Please use apt-cdrom to make this CD-ROM recognized by APT. apt-get update cannot be used to add new CD-ROMs
Err:3 https://debian.csail.mit.edu/debian release-code-main InRelease
  Could not connect to debian.csail.mit.edu:443 (128.30.3.141). - connect (111: Connection refused)
Hit:4 https://packages.crunchbangplusplus.org/buster buster InRelease
Reading package lists... Done                                    
E: The repository 'cdrom://[Debian GNU/Linux 10 _Buster_ - Official Snapshot amd64 LIVE/INSTALL Binary 20190712-12:32] buster 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.

Answer 1

Comment out the install from cd line:

deb cdrom:[Debian GNU/Linux 10 _Buster_ - Official Snapshot amd64 LIVE/INSTAL

Then
apt update

Answer 2

Register sources and update the list of packages. Here are my sources.

$ egrep -v '^$|^#' /etc/apt/sources.list
deb http://mirror.yandex.ru/debian/ buster main non-free contrib
deb-src http://mirror.yandex.ru/debian/ buster main non-free contrib
deb http://security.debian.org/debian-security buster/updates main contrib non-free
deb-src http://security.debian.org/debian-security buster/updates main contrib non-free
deb http://mirror.yandex.ru/debian/ buster-updates main contrib non-free
deb-src http://mirror.yandex.ru/debian/ buster-updates main contrib non-free
deb http://mirror.yandex.ru/debian/ buster-backports main contrib non-free
deb-src http://mirror.yandex.ru/debian/ buster-backports main contrib non-free
deb http://ftp.debian.org/debian/ buster-proposed-updates main contrib non-free
deb-src http://ftp.debian.org/debian/ buster-proposed-updates main contrib non-free