Firstly, to create the thesis statement you should select a person that you consider to be a 'person of magnitude'. For example, let's select Mahatma Ghandi.
Secondly, you need to write two supporting details for the thesis statement. This means that you have to search information about the person you chose, in this case, Mahatma Ghandi, and then select two things that he has done that you consider to be what makes him a 'person of magnitude'. For example, Ghandi was a very important figure in the Indian independence movement against Britain. Also, Ghandi was non-violent so he fought peacefully and that is why he is so well-known.
Finally, you have to use transitions in your text. You can learn more about transitions in the following link https://brainly.com/question/2372495?referrer=searchResults
In conclusion, you need to select the person and search information to create your thesis statement. Then, you have to write a coherent text using transitions and writing down the information you first selected.