I mean yes they all build off each other. However, the basis for all science is logic? You take logic and observation and you use math and other previously proved physics ideas to create concrete proofs, then use more logic and observation to prove your findings. Repeat forever.
However, I said computer science, which outside of the physical hardware it’s entirely just math and logic. Yes, when trying to get performance the logic you look at includes the hardware and all its design and limitations. However, it’s not needed for most people or even this conversation. It’s an included practice when talking about computer science and isn’t necessary to mention it.
Pure computer science is entirely about using the hardware given and making logical decisions utilizing math to move and generate data in efficient ways. Some intersection occurs here when trying to do say, realistic physics simulations, RNA folding simulation, molecular simulation, etc. Those do inform each other but mostly about how to reduce the math complexity while still generating accurate enough data.
For the person designing CPUs and all the support hardware, then physics influences their designs by a lot which is where the real intersections begin.
You might have grabbed the wrong iso. There are two ISOs for Ubuntu, one is desktop which comes with a desktop and the other is server which only comes with a text console.
You can install a desktop onto a server image if necessary, however I would recommend just using a desktop iso and don’t bother with adding on and setting up all the desktop software.
If you want to be able to select text, copy and paste, I just SSH from Windows Terminal or Mac iTerm2
Alternatively if it is a desktop iso then you might have accidentally installed a package that broke things or have gone a tty interface. There’s so many different possibilities it’s going to be hard to help more.