If you want your data to be versioned then you need to open ArcCatalog browse to your Database Connection then select the feature dataset(s) and/or tables then right click and choose register as versioned.
If you do not want to version your data then in ArcMap go to Editor > Options > Versioning tab and uncheck the "Edit a version of the database with the ability to undo and redo." option.
Also, you have a data layer that is not found in your table of contents. Any layer with a red exclamation mark next to it means the data can't be found. Right click on the layer and choose Data > Repair Data Source... to browse to the data's location and repair the broken link.
