The details may be slightly different depending on what window manager you are running and what terminal emulator you use. I am using KDE for my window manager and I use Konsole as my terminal emulator. This example will create a desktop icon to run the top program in a terminal window directly from a desktop icon.
First create a desktop shortcut pointing to the terminal emulator that you want to use. In KDE you would position the mouse pointer anywhere on the desktop and press the right mouse button. A menu will appear. You select Create New -> Link to Application. A window will appear.
There is a box with the text "Link to Application". Change that text to whatever title you want the desktop shortcut to have. In this case I would enter "top".
Click on the icon in the same tab. A window will appear showing the available images for the desktop shortcut. Choose whatever image you want the desktop shortcut to have.
Select the "Application" tab.
In the box labeled "Command" enter konsole -e top.
Click the "Ok" button.
You will now have a desktop icon with the image that you chose and the title that you entered in the general tab. When you click on the icon a konsole window will open and it will automatically start running the top program. When you exit the top program the konsole window will close.
If you want to use a different terminal emulator then you will have to look up the method of passing a command argument to that terminal emulator software. In most cases with any Linux software you can enter the command at a command line with the --help argument.
Whatever window manager you use will have a very similar, if not exactly the same, procedure to create a desktop shortcut.
The same is true about using a particular environment setting for your terminal emulator. You should be able to open your terminal emulator software, create the settings that you want to use, and save that as either the default settings or as a named profile. Then your desktop shortcut would have whatever argument is required to have those settings restored passed on the command line. The konsole application uses the --profile argument for this. If I had run konsole, created settings that I wanted for the top utility such as fonts, then saved that setting as a session profile named top, I could invoke that with the following command.
konsole --profile top -e top
This may have been more than you asked for but your question appeared to be asking how to select a specific terminal emulator of your choice and how to select a specific encoding. I hope that I addressed both of these issues clearly.