You can mark your stories as favorite and follow them by following the below mentioned steps:

Step 1: Open the story you want to follow or mark as favorite.

Step 2: Tap on the star icon from the tab bar at the bottom of the screen.

Step 3: A menu will pop up. Tap on "Follow" to follow your stories.

Step 4: Tap on "Favorite" to mark your stories as favorite.

Step 5: Green icon next to them shows that you are following them and have marked as favorite