I just downloaded Scrivener and I want to start using it to work on a story. In the tutorial, I noticed that there was a “Start Here” icon in the binder. I’m wondering if it’s possible to set a “Start Here” marker in the text if I have to stop working on something, etc.
Scrivener opens every file exactly at the position where you’ve left it. Automagically 
OK, thank you.
For a more permanent marker, you can also put down an inline annotation or comment to make it easy to return to a spot in the future. You’ll find these features discussed in Step 19 (inline notes) and Step 5h (comments).
And just to make sure it is clear, the thing you see in the tutorial is just an ordinary file, nothing special about it. If you want to use a file as a marker feel free to do so. Just select the section of your manuscript that you stopped at in the Binder, hit the return key to make a new file and name it. You can give something a custom icon by right-clicking on it, to help it stand out in a long list.