How to Add Web Part Zone in existing Page

Question

I have a page which has already a web part and I need to add another web part zone.

Can you please help me with this?

Answer 1

What's the problem with you?

You can add another web part by clicking "Add a Web Part" button as your screenshot.

Update:

If your page is in Site Pages library, you can go to SharePoint Designer->Site pages in the left pane->find the page and Edit File in advanced mode.

Add insert Web Part Zone via click the botton:

Answer 2

In Order to add a new WebPart Zone you need to create a custom Page Layout and use that page layout to create your SharePoint Pages OR you can edit your page in SharePoint Designer and add below code snippet to it.

Reference: Create a Custom Page Layout in SharePoint.

Then you can add below code snippet to add webpart zone to your custom page layout:

<WebPartPages:WebPartZone runat="server" Title="TestZoneTitle1" ID="TestZoneID1">
    <ZoneTemplate></ZoneTemplate>
</WebPartPages:WebPartZone>

Reference: Add a web part zone snippet in SharePoint.

Notes:

1. Make sure you are putting this snippet inside <asp:Content ContentPlaceHolderId="PlaceHolderMain" runat="server"> block.
2. Make sure you are passing different ID to webpart zone if you are adding multiple webpart zones on your page.