It seems like you are exploring the four branches of the tech tree. One of them is named "Engineering" and will let you build various things for your ships. You are on the right track.
I don't know how to do links within the forum, but at the top level is a pinned post named "Helpful Links", There is a manual there. Also, the manual is available in the lower left corner of the game's Start screen. It should help you with many of your questions. Have fun!
