Since the primer release of ArcGIS Pro a lot of Pro-related materials and files where uploaded and shared publicly.
These files could help you in your work, hence, saving you time and exposing features and capabilities of the software.
That staff includes (I didn't write all):
- Project Package (ppkx)
- Map Package (mpkx),
- Layer Package (lpkx)
- Project file (aprx)
- Project template (aptx)
- Pro Style (stylx),
- Rule Package (rpk)
- Geoprocessing Sample
For instance, if you want to search Project Packages, you can write "Type: Project Package" in the Search ArcGIS thingy:
Using the "Type:" flag will filter a lot of noise, but in some cases you'll get cluttered results, such as when searching for Rule Packages. In that case, some of the results are suited only for City Engine.
As for the Pro Add-Ins, the current richest source is currently arcgis-pro-sdk-community-samples in GitHub.
Another good resource for Pro materials is ArcGIS Solutions, where you could find complete ArcGIS Pro solutions for all kinds of industries and subjects (May be hard to filter the results). These solutions may contain Add-Ins, Tasks, Templates, Data samples/structures, etc.
Of course you can always look in the Geonet Pro Community.