To parse the subject line you can use the ‘string.contains’ method. After that, you can use control structures and work accordingly also its good practice to convert the subject to lowercase so that you don’t miss a match due to text formations.
Looking for UIpath material from basics! Refer to this video on UIpath provided by Intellipaat:
Here is a screenshot for your reference:
Now to address the SharePoint, you can either use the custom activities from the SharePoint Package or you can simply work with web-automation and activities like ‘set text’ to populate parts of the page.