How can I write a thesis about the theme of an individual’s attempt to determine his or her own destiny in Macbeth?

When writing a thesis statement, a good way to begin is to analyze exactly what the question is asking for. Some examples can be: comparison/contrast, informational, persuasive, analytical, etc. When you know what the question is targeting, you can then begin to formulate how you would answer the question and think of examples in the text that will support your response. 

You may find that, at the beginning stages, you end up with a thesis...

When writing a thesis statement, a good way to begin is to analyze exactly what the question is asking for. Some examples can be: comparison/contrast, informational, persuasive, analytical, etc. When you know what the question is targeting, you can then begin to formulate how you would answer the question and think of examples in the text that will support your response. 

You may find that, at the beginning stages, you end up with a thesis that is either too broad (meaning the topic is too large to be covered in the time you have or for the length guidelines of the assignment) or too narrow (meaning you don't have enough to write about without becoming repetitive). It's okay to change your thesis statement as you write; in fact, many writers are constantly revising the wording and scope of the thesis statement as they write.

For your specific question, ask yourself first: Do you think an individual can control his or her own destiny? Whether you answer "yes" or "no" will help guide the position your thesis will take. For example, if you think that yes, an individual can control his/her own destiny, a thesis statement that might work for you is:

Macbeth's attempts to control his destiny were successful temporarily, but the clumsy execution of his attempts led to his ultimate death.

If you think that destiny is predetermined and any attempts to control one's fate are futile, you may focus your ideas differently:

Though Macbeth attempted to control his destiny and believed he was acting of his own free will, he was actually a mere puppet for others. 

Of course, you may feel that Macbeth's attempts to control his destiny were completely successful; he did become king, after all. 

Macbeth executed his will to control his own destiny on several levels, each of which contributed to his ultimate success of becoming the King of Scotland. 

These thesis statements are just ideas for you to work with and think about. If one stands out, try writing an outline based on that thesis and see how it goes. If you think you'll struggle with examples/support, look for ways to expand the thesis. If it seems too broad or abstract, perhaps look for ways to narrow it more.