Rapid Learning Path 4.3.1 Create and Connect Entities

Hi Everyone, I am currently in the Rapid Developer learning path 4.3.1 and have a question. When I am creating a new entity and start to add the attribute I only have the option of Boolean and Enumeration? String, DateTime, decimal, etc. are not there. The attribute I am creating is a string but I do not have the option to select it from the Type drop down box. Has anyone had this happen? Any suggestions?   Thank you, Emily