Saving a project to my computer

You really need to take some training, whether by watching tutorials or in any other way!

As I tried to explain: saving a file is not the same as publishing a file. You are at this moment creating a project in cptx-format. There is no way to use that for uploading to any LMS. You have to Publish the project, which is totally different and will result in a folder with quite a bunch of files. Since you talk about Blackboard: do you want to publish a package, that will not report quiz results, grades or will you create a SCO, which will transfer results and can be included in the Gradebook? I know, you probably don't understand what I'm asking, but using an eLearning tool is not the same at all as writing a simple text in Word. You need to know at least some basics.

Since you don't see the option 'Publish to Computer' it means you are creating a responsive project. Do you know if you used the Fluid Boxes workflow or the Breakpoint views workflow? Do you realize what a responsive project is, and which steps are needed to create it? Why did you not start with a simple, normal project?

How is Blackboard set up: do you need SCORM 1.2 or 2004? Does it accept HTML5? Which browsers will be used to watch the course?