If you would like to remove the white border from your plat map, you can perform a raster clip to crop it. There are a few different approaches you can use to clip rasters, but for the purposes of our assignment, we'll quickly create a polygon then clip our raster to the polygon. We'll complete this process via three majors steps: we'll create a new polygon feature class in our project's geodatabase, start an editing session to draw the polygon, then clip our raster (e.g., plat map) to the polygon that we created.
ArcGIS Pro provides an editing pane if you want to create new features, edit existing features, standalone tables, etc. You will want to start an editing session any time you create or edit data in ArcGIS Pro. This will provide you with added security in the event you make a mistake and need to cancel your changes. Changes made in an editing session are temporary until you save your changes and stop the session. If you add / edit data in ArcGIS Pro outside of an editing session, the changes that you make are permanent.
The edit button doesn't initially display in the ArcGIS Pro menu bar. You can change this setting by completing the following steps:
Go to the Edit tab in the ArcGIS Pro menu bar.
Click the Editing Options icon located in the lower-right corner of the Manage Edits group.
In the Editing Options window, scroll down to the Session settings. Click the Enable and disable editing from the Edit tab checkbox. Click OK to close the Editing options window.
The Edit button will now appear in the ArcGIS Pro menu bar. Highlight the map layer you want to edit in the Contents pane, then click Edit to start an editing session.