Do not take these as absolute truth, for they are mere recommendations:
1. Read through the text. If you come across words you do not understand, since Shakespearean language can indeed be unsettling, your text should provide you meanings to works either at the bottom of each page or at the end like an index. If it does not, it would be helpful to get a version that offers this.
2. Reflect. What do you think the play is about? Perhaps consider this in terms of a thesis. I suggest to do this after you complete your reading because (a) you are seeing things from a holistic point of view, that is, from the context of the whole play and (b) it helps you develop your own opinion of the play rather than having a pre-determined idea in your head.
3. After doing so, note what themes and events you found significant and may support your opinion. Three or four themes and events would be enough.
4. It certainly does not hurt to think about the characters as well, especially Hamlet, since it is possible you may receive a question centred on him. For example, Hamlet struggles for most of the play to unite thought and action in achieving revenge. What do you think about this development? Do you agree with Hamlet's choices throughout the play? Feel free to extend this to other characters like Gertrude and Claudius.
5. Once you have cultivated some thoughts about the themes, events and characters in the play, jot down some quotes you could utilise in relevance to these. It will aid in structuring your essays later on.
6. Repeat the first step if more knowledge is required. Reading the play comprehensively is vital to your overall understanding.
Good luck and you may receive other advice, so take mine with a pinch of salt and decide for yourself whether it would suit your style!