Form Field Select Field - How can I load or change the selections based on logic

Site URL: https://www.phgagolf.com/event-signup

On my form I have a select field (Event) that contains the upcoming events that the user can select.  What I would like to do is either a) dynamically load the events from a Google Sheet or other source that can be programmatically maintained,  or b) remove events from the selections based upon date.  Once an event date has past I don't want the user to be able to select it.   I know I could go in and update the form manually occasionally but I would rather have it happen automatically.

Use Google Sheets is an option, is has published url that can be fetched as data source, or do you create events on the page? Can also use summary block to get the upcoming event and parse it into the form via code

I have a form (https://www.phgagolf.com/supplemental-form), pick the Supplemental Entry Button, that has select fields on it to allow the submitter to pick partners from a roster of members.  Each of the select fields contains the same list of members.  You mentioned a method to use Google Sheets to fetch data from, I have limited coding skills, is there an example I could look at to build from ?

Thanks