You can use dpkg to view a deb file

dpkg --info /path/file.deb

to get general information, and

dpkg --contents /path/file.deb

to get the files (programs, libraries, documents etc) listed:

Edit: You can also view a deb file with emacs

emacs /path/file.deb

and that way get into the different parts of the deb file

Example from ppa:mkusb/unstable which I am developing. The following command

emacs dus_22.0.7-1ubuntu1_all.deb

brings you to a table

   Mode    User/Group   Size        Date       Filename

--------- -----/-----  ----- ---------------- ----------------

rw-r--r--     0/0          4 2022-06-03 17:03 debian-binary

rw-r--r--     0/0       1420 2022-06-03 17:03 control.tar.xz

rw-r--r--     0/0      58968 2022-06-03 17:03 data.tar.xz

--------- -----/-----  ----- ---------------- ----------------

You can enter the control tarball to see the same as dpkg --info and enter the data tarball to see the same as dpkg --contents and furthermore very conveniently enter each of the files if they are possible to read (and most of the dus files are bash shellscripts).

Edit 2: Install package from deb file

The command line

sudo dpkg -i package.deb

should install package and make its program(s) available like other programs, if that is what you want.