Is it possible to define a rule that allows the end user to fill out the form, but not pay yet

Also, is it possible to define a rule that allows the end user to fill out the form, but not pay yet. Almost like a pre-registration
First question would be pre-registration(doesn't go to payment part) or full registration(does go to payment section

f you need to offer payment by check or PayPal, here is our guide on how to set it up so that the user is not redirected to PayPal when check is selected:

https://www.jotform.com/help/120-How-to-Set-up-Paypal-Along-with-Other-Payment-Options

It would take a very slight modification to your form.  You would need to set up your tournament fees using regular fields (single choice, multiple choice, number field, etc), assign those options calculation values:

https://www.jotform.com/help/301-How-to-Assign-Calculation-Value

Calculate the total using a calculation field:

https://www.jotform.com/help/259-How-to-Perform-Form-Calculation-Using-a-Widget

Then pass that total to your payment field:

https://www.jotform.com/help/275-How-to-Pass-a-Calculation-to-a-Payment-Field

That way, you can have your total outside of the payment field, the conditionally show the payment field depending on whether or not they want to pay at that time.