ArcGIS Pro — Creating a Project Template 
To create a Project Template in ArcGIS Pro, simply search for “Project Template” in the command search bar:
Or, if using default ribbons, select the Project Template button under the Share tab:
One on the tool dialogue box, the first option is to share the template to either an online account (ArcGIS Online — “AGOL”) or saving the template as a file. For simplicity, it is recommended to save the template as a file and store it in a memorable place on a department-wide shared network drive:
There are a few additional options, but they should not be necessary to enable unless you specifically know you will need to:
Finally, to create the template, you will need to “analyze” the Geoprocessing tool for any possible errors:
If any errors appear that are not immediately apparent on how to resolve, you can reach out to the Bedford County GIS Office for assistance.
If no errors appear, you can click “create” and an .aptx file will be created at the specified location. Once the tool is finished running, you can select “Manage the package” to see the .aptx project template in Windows File Explorer.
Once you have confirmed that .aptx is created, navigate back to ArcGIS Pro and select the Project tab (this is nearly an identical page to the default screen if no .aprx was selected when opening the software):
On this screen, select the “Start with another template” on the right side of the window and navigate to the .aptx file you have just created:
This will prompt the user to specifcy the name and location of a new .aprx file, which will be the (new) user’s personal copy of the ArcGIS Pro project file:
A new project with all of the same configurations of the original project will then open. Any changes to the project (but not any underlying accessed data) will not affect the original project or template.
For additional information, please see ESRI’s help documentation for creating Project templates.
https://pro.arcgis.com/en/pro-app/3.1/help/sharing/overview/project-package.htm