minimum days to be employed to Activate Secret Clearance

Hi all My current job requires Public Trust (high security). I worked in IT. Last time I used my Secret (DOD) was in June 2023. I have heard it’s good for 2 years. I have a job offer as a Security Guard which requires Secret. How long I have to be employed as a Security Guard to change the status to “Current” Secret Clearance. Is there a minimum days requirement.

Also I was placed on CE on 11/03/2019 so a PR is not due until 11/02/2024
If I don’t Activate/Current my Secret by 11/02/2024 will I lose my Secret, Do I have to employed and only an employer can start PR for Secret.