I installed Postal 1 on my laptop a couple days ago with the offline installer i cant open the game i click on it and nothing happens even after installation.

I suggest you to launch the game in the terminal in order to know why it doesn't run: some error message should show up.

what are the commands to do that In the Terminal?

Call me stupid but uhh i tried multiple command things
first it was cd<Home/GOG Games/Postal Classic and Uncut/game
then it was this cd<Home/GOGGames/Postal Classic and Uncut/game
then the last one is this cd<Home/GOGGames/PostalClassicandUncut/postal1
and none of these i did not work :(
the "cd <path/to/the/game" thing got me confused so im not sure what to do now
Edit: i forgot the this > and it gave me a Syntax error near unexpected token 'newline'. what does that mean?

it gave me a too many arguments
this is the command that i typed
cd Home/GOG Games/Postal Classic and Uncut/postal1
i think im slowly losing hope on this
and yes the file is postal1 when i click run on that it does nothing

I didn't suggest you a single command, but two different ones. One for changing the directory and one for launching the game.
The "cd" command says that you input too many arguments because the Linux terminal doesn't understand spaces in the folder or file name. Command line completion can help you. Anyway I suggest you to read some guides about the subject such as this one. That's why I suggested you to launch the game in the terminal: in order to get some output and understand why it doesn't run.

im go show my screenshot of i have so far i tried _, and i tried " not sure if the ss i sent will help im go read the 2 wiki things

Based on your screenshot, you're typing things incorrectly.

open a terminal (either use the menu or [Ctrl + Alt + T].

This *should* place you in your home directory ( /home/username/ ) - sometimes you will see this written as: "~/". The "~" is short for your home directory

next command "ls" will show you the contents
--- hint: if you prefer a "gui" install Midnight Commander and navigate around in the terminal as if you were in nautalis/nemo/dolphin etc.

One of the directories should be your gog installs. If you have spaces in the name you will type it like this:

cd "gog games here"

that will drop you into the next level. Somewhere in there is your postal game. cd again into *that* dir. Keep going until you get to the dir with the program you want to run.

then the command to actually run the program (assuming the name is postal1) would be ./postal1

Remember Capital Letters matter!!

"Cat" is not the same as "cat"

hope this helps