Hi kieranwatts and welcome to GMATClub
You have some of the information in the following post:everything-you-need-to-prepare-for-the-toefl-100641.html
There are 4 sections and each of them are graded from 0 to 30. Therefore, the exam is graded from 0 to 120.
Usually, the most difficult sections are Speaking and Writing, which need much practice. You can check in the above link some tips to improve your score in such sections.
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