In this world, the mind can bring all things into existence. As long as you have a medium and can convert energy, you can create a world.
Of course, what you create can only take shape when the conditions allow it. Not everyone among the interstellar population can meet the requirements for projecting the mind and creating things. You need a certain level of mental power, or a unique special ability, to pass the test and gain authorization.
With authorization, you can create your own System: a virtual realm of your own, or a System to supervise your studies.
The saying "With a single thought, flowers bloom and all things come into being" applies to the virtual realm.
"I never thought a car accident would drag Wang Tianyou into my own timeline. Turns out he was a native of this world."
A stranger in an unfamiliar place, he finds it incredibly difficult to survive in this technologically advanced world, where almost everyone carries a weapon.
In the end, he finds the path that's right for him and reaches the pinnacle.
Matter formed from the mind can only create a domain within the rules, where you are its master and rule over the world. In essence, it is nothingness, but countless worlds can cycle through rebirth. In the interstellar world, even time travel exists.
All causes and effects leave traces. Choose your own path and predict everything.
Technology serves to make life better.