A family of Microsoft word processing software products for creating web, email, and print documents.
Define a new style with the same attributes as your Level 1, but without the numbering and use that style for the headings that you do not want to be numbered.
If you want the un-numbered headings to be included in the Table of Contents, you will need to assign the appropriate TOC level to that style in the Table of Contents Options dialog that is accessed by expanding the Table of Contents dropdown in the Table of Contents section of the References tab of the ribbon and then clicking on Custom Table of Contents and then on the Options button on the Table of Contents tab of the Table of Contents dialog.
NOTE: There are a number of good reasons for using the built in Heading # styles for your numbered headings by linking each level of the multi-level list to the corresponding Heading #