Hi Thalia,
Thanks for posting your question in the forums. There is a 100MB file-size limit for uploading files to the Adobe PDF Pack online service. If you find that PDF Pack isn't going to work for you, you are welcome to cancel your subscription (and since it's within 30 days of purchase, you're entitled to a full refund).
You might consider an Acrobat subscription (which is software that you download and install). You would be able to create PDFs locally, without having to upload your files, so you can avoid and file-size limitations. For more information, see www.adobe.com/products/acrobat.html. (You can try it for 30 days for free.)
Best,
Sara