When I saw this "First time making Tamales", my memory transported me back to my all time
worse cooking nightmare, so I have some basic advice.
Do not attempt to prepare the filling and make the Tamales on the same day.
Get someone to help you share the "fun".
Good luck. I now leave Tamale making to the expert Mexican families around here, and gladly pay them for their labor intensive expertise, and delicious Tamales.