I need to create a new self signed certificate because an old one is expriring but I am not able to click the button

I am attempting to update the Campaign Member status depending on the edit of a picklist field on a custom object called Application. Applications records have the Campaign ID and Contact ID as lookup fields in them.

For example, ABC applies to one of our programs, in Salesforce an application record and campaign member record are created for ABC. When the application status field is changed from New to Rejected, I want the campaign member status field to change from Registered to Denied.

I'm pretty sure I can use process builder with flows to do this. As in have a process that runs when an application is edited and use flows to capture the Contact ID and Campaign ID on the Application record as input variables to use in the process builder to locate the Campaign Member record and update it. That's my loose understanding. Can anybody help and give me more indepth directions?

I need to create a new self signed certificate because an old one is expriring but I am not able to click the button

Hi All.
We received the following (see below) certificate expiration notice but when I look for this in our Certificate and Key Management section, within Setup, I am NOT able to find any such certificate with this Expiration Date.  Should I be looking elsewhere?  
Thank you for your time and advice.

"You have one or more certificates in your Salesforce org Navin, Haffty & Associates 00D2E000000no3I that will expire soon. Review the list below and visit Certificate and Key Management from Setup to make an update.

- SelfSignedCert_15Apr2019_184313, Self-Signed, expires on 4/15/2020. Warning: This certificate will expire in 30 day(s)."