In APA 7, headings are bolded and written in Title Case, where all major words are capitalized. For most college writing, you will probably only need the first level of headings to describe the major sections of your paper (and maybe the second level for subsections inside of your first level headings).
First Level of Headings (Including Your Title!)
Your paragraph begins indented on the next line.
Second Level of Headings
Your paragraph begins indented on the next line.
Third Level of Headings
Your paragraph begins indented on the next line.
Fourth Level of Headings. Your paragraph begins right here on the same line.
Fifth Level of Headings. Your paragraph begins right here on the same line.