If you're submitting in the TV Pilot + Series Bible format you'll need to combine these two documents in to one PDF to be able to upload it to our system.
A simple Google search on "how to combine PDFs" brings up a host of answers and solutions, and we have used the link below successfully to combine PDFs in the past.
https://smallpdf.com/merge-pdf
You can also visit YouTube where, again, there are a host of videos showing FREE and easy ways to do this.
https://www.youtube.com/results?search_query=combine+pdf+files+into+one
No particular technical skills are required, and there are multiple free solutions out there.
It's a simple case of Googling/YouTubeing...