To automatically open a terminal application in a terminal window after logging in to your desktop, you will need to set Terminal=true in the launcher.
Unfortunately, the "Startup Applications" dialog in the standard Ubuntu desktop does not allow to set this using the graphical interface. You may have more luck in the Mate desktop. But if also there there is no checkmark to set the program to run in a terminal, then still continue use the dialog to create the startup launcher by filling out the Name, Command and Comments fields. As "Command", specify the full pathname of your script. Tip: If you use the "Browse" button to navigate to your script, the full path will be filled automatically.

When you click "Add", a .desktop launcher will be created in the directory .config/autostart in your home directory. Navigate there (make sure to enable "Show hidden files" because the hidden directory .config is not by default shown), and open the launcher with a text editor. Change the line Terminal=false to Terminal=true, and if no such line is there, add it.
Caveat This will cause the script to automatically run in a terminal. If the script terminates, also the terminal will be closed. Thus, if you want the terminal to remain open so you can see the output, add a command that keeps the terminal open, e.g. read -p "Press enter to continue".