While you cannot print an entire proposal prior to submission, you can download the files from the Bonfire Portal prior to hitting the Finalize and Submit button. Under Step 2: Upload Your Files section, to the right of each document you will see a download icon that will re-download the document in that slot for your review.  

NOTE: After you hit "Submit and Finalize" you have the ability to un-submit your proposal in order to edit any documents that may need updating. Please see the following article for more information: Can I un-submit my bid once it has been submitted and finalized?