To link chapters together, you need to create a Title Page for a series or serial. Use the|++Organizer| link at the top of the screen. After you have saved it, you can link it to your Author Page with the |Outline| tab. Open Outline and search for your Author Name in the rolldown. Then Save again.
Then to link the chapters in, use the |Outline| tab while viewing the story. This will bring up a list with all the titles and chapters currently linked together on BC, a lot. Click on the window with the list then type the first few letters of your title for your story and it should scroll down to make looking for the right one easy. Just highlight the title you want your chapter linked to and click save.
There's a weight button to help you get chapters in the right order, chapters 1-9 should have weight 0, 10-99 weight 1, 100-999, weight 2, etc. You can give appendices and codexes to your story weights of 8 or 9 or something to be sure they appear after the chapters, or -1 or -5 or something if you want them to appear before the chapters.
Hope that helps! If you make mistakes, I or one of my editors will probably catch it within an hour or two and fix it for you. :)
If you just post chapter two of a multi-chapter story without doing any of this, one of us will probably do it within a day, giving you time to step up and do it if you can.