I don't think you have yet learned how to use the error console.
Which browser are you using?
I personally prefer Chrome. It will show you your errors even if you turn on the debugger after you have started using the page.
-- Bring up that page in Chrome
-- Hit the F12 key to bring up the debugger.
-- Click on the CONSOLE tag in the debugger
-- Without entering *ANY* data into your form, hit the Calculate Now!
-- Look at the console section. It should say (with "filename" replaced with your actual name):
Uncaught ReferenceError: Senior is not defined filename.html:119
-- Click on the "119" there.
var senior = Number(document.getElementById('seniorTicket').value) || 0;
var seniorprice = 9.50; // (no $ sign!!)
var seniorcost = Senior * seniorPrice;
is *NOT* the same as senior
Fix that error. Hit REFRESH. Hit "Calculate Now!" again.
See your next error.
Keep at it. There are several.