How do I change the titles of events?

When I share the form with my vendors etc. It still says an OLD event and shows the OLD poster... PLEASE help!

Are you referring to this form:

If yes, you can change the poster and the form title from the Form Builder as shown below:

Change the header title from the field properties:

Regarding the poster, you will need to add a new/updated one:

To update the name on the browser tab, you will need to change the page title from the Form settings:

Related Guide: https://www.jotform.com/help/373-How-to-Change-the-Page-Title-of-the-Form 

Do review and let us know if you are referring to this.