Those fields are a mathematical tool to describe what is going on in a specific way - for example making the local character of particle interactions obvious - but there is no evidence that there are actually any fields. Quite the opposite, a good reason to doubt that those fields are real is that they have Gauge redundancies, i.e. one physical state has several different mathematical representations.

So basically a certain energy allows to bring forth certain particles into being through laws of physics. How does the universe know the laws, how is it encoded? Sorry if I am vague!

The universe simply is, and “laws” is what we know about what/how it is. For example, the law: “Things consist of atoms.” The universe does not “know” this law, we do.