My suggestion is you just go ahead and start reading those texts on their own and see what you make of them. Allow yourself to grow with the texts. This isn't mathematics or physics where you need to go from A to B to C. In philosophy you can spend a lifetime reading any great book over and over again.

I see the study of philosophy as a certain path. When starting, one should take steps through the different subjects.

Often my schools start with ethics, which I find appalling. Ethics is quite practical in modernity, but in starting there you lose your intellectual footing and your arguments die quickly.

The order:
1: Existentialism
Existence predates knowledge and morality, and only through recognizing where and why we are, can we determine what to do.

2: Epistimology
This is a close second and I can think of many reasons why it could be first. I see epistemology as the search for truth about truth. If you do not know what it means to 'know' than any moral arguments that you 'know' can be dismantled.

3: Ethics
If you have made it so far as to believe in the existence of other people, than you must attempt to find what it is you should do with these people.

4: Aesthetics
If you have not murdered everyone and you are a member of society, than it is time society determine what is desirable beyond its ethical parameters.

Lucky for you, Nietzsche covers the whole four holes. I do recommend Kierkegaard before Nietzsche however, as he covers the main basis while building up religion, and Freddy will later deconstruct this.
From there you will find many routes from which to choose.

Just go straight into Nietzsche. If you find something you don't understand... Google it. dictionary it.

Albeit you have understood somehow that Nietzsche was influenced by Schop... You don't need to completely understand the precursors to understand each individually. You will find in Nietzsche that the philosopher is radically himself, if he is a true philosopher