Woocommmerce custom email notification

I have a question about woocommerce code I hope you could help because I found this item on your site so I give it a try:


We are trying to build in something when an order is “processing” for lets say 2 days it must automatic send an email to the customers that we think on them and the order is almost on their way, so I found also this, but I can’t figure out can you maybe help?