PDFgear supports you to insert a blank page into the current PDF document. Please follow the steps below to insert a blank page:
Step 1. In the Page tab, click Insert Pages and then select Blank Page.

Insert a Blank Page
Step 2. Adjust the page size, orientation, and position before clicking OK.

Customize the Inserted Blank Page
Alternatively, move the cursor to the page where the new page will be added before/after, click the add icon, and select Blank page.
PDFgear also supports inserting pages from files, including PDF, Word, and Image files. Please follow the steps below to insert pages from files:

Insert Files to PDF
Step 1: In the Page tab, click the Insert Pages button and select the one that corresponds to your file.
Step 2: Navigate to your file and select the one you want to insert. Set the insert mode, including range, subset, and position, and you should be able to see the PDF after insertion.
Alternatively, move the cursor to the page where the PDF will be added before/after, click the add icon, and select Insert PDF/Word/Image to PDF.