You can definitely add new sections to the Public Profile or Business Plan areas of your profile.

You will notice that after every section, there is a page break that is quite invisible. Mouse over it and the + Add Section will appear.

Click on that and new options will pop up for you to choose what type of section to add. You can select Text/Images, Team Members or Document section. There is also a cancel button if you changed your mind.

The new section will be available after clicking the section you want to add.

Trust this helps.