Email automation set up from Google sheets

I want to insert data from a sheet into a pdf and an email, then attach the pdf and send it, then have it write a "sent" response into the sheet. I want a basic template that I can build on in future. For example, if the email has to include more data or the invoice pdf template changes it should be modular/dynamic enough to change change without too much trouble. Then just take me trough it or have a 1 page doc so I can make the future changes myself. I have coding background.