Upto what I understand
Create a form like the one you attached in pdf above with necessary text fiels, label, buttons, etc. Then use the Barcode scanner to scan the barcodes on trailers and dolly. After scanning of each barcode, set the text to respective fields in the form using AfterScan event of the barcode
Documentation for barcode scanner 
After scanning is done and you have got and set the text in respective places, use the extension Create PDF file Extension. Layout to PDF by @Juan_Antonio to covert your form layout to pdf.
Once the pdf is created you can email it to anyone you want
This is on what I understood from your reply above