Hello Dear

There are two ways to creating pipeline stages in odoo studio The first one is by selecting it from the dialog box at the beginning of creating the module 

The Second one is by pressing the add a pipeline stage from inside the module after creating it

The difference between these two is that the first one creates stages model in which you can add-edit-remove stages, While the second one creates a selection field without a model.

If you used the first method then you will find a stages model in the configuration of your new module

If you used the second method which I believe you did you will have to go to the field it self and change the sequence of the states by openning the studio and pressing on the stages field then pressing on more

and then you will find Selection options with your status in it you can change the status by adding removing editing or changing the sequence