Let me suggest one technique for starting a personal essay. Remember that for a story to be powerful and memorable for the reader, it must be powerful and memorable for the writer. So sit back and go down memory lane and make of list of those memories which stand out for you. They could be good or horrible. List the top 5 or 6 or 7 of these. Now look over each. Is there one that stands out as something which changed you? Or strengthened you? Or tested you? If so, that is your topic, and a description of that moment/incident/scene will become the first paragraph of your personal statement. The essay itself will then be your transition to a stronger you, a changed you, a you who has overcome some issue, nemesis, flaw, or challenge.
If your desired study resources do not fit the above mentioned requisites, you should not stop looking for preparation materials as there are ample choices available with respect to these. You must remember that seeking free prep materials is a challenge and there are no comprehensive preparation materials available. You have to arrange materials from several sources to make your study resources comprehensive. However, in the following part of the article, you can find out some useful links to websites where you can browse through some trustworthy sample papers, study materials and practice questions for TOEFL.