Troubleshooting PDF Export Failure in InDesign: Page 1 Issue

What content has that page, if graphics or images, which file types, linked or embedded?

Try exporting from 2 on to make sure it isn't present on other pages too. If only on pg1, remove elements & export until you find the troublesome one. Sometimes in the Background Task panel it will tell you the error (if a font cannot be embedded, etc.).