Yes you can do this from the script editor (from the spreadsheet go to tools>script editor). Look for the code in red which is normally the writing that would be visible and edit this however you like. The variables (EG ${row[4]} ) are the bits that change depending on what the teacher put in their request so probably best to leave them as they are.
If you go to calendar.google.com and find the shared calendar in the bottom left, click the three dots next to that calendar and go to settings and sharing. Scroll down to where it says Calendar ID which will look like a long email address. Copy that and go back to the code in the script editor and paste it at the top inside the speech marks for the CALENDAR_ID variable. The next time it runs (when someone fills in the form) it will create the event in the calendar you just specified.