is this pdf service free or paid subscription ?

Please give the EXACT names of what you have, there are many similar things. There are lots of things with DC in the name, some paid, some free, none called Adobe DC.

Please explain the “notice if payment monthly”. How does it come, what are the words? Did you ever give Adobe your credit card details?

Adobe DC,,, Adobe Reader,,, etc.. downloaded them all and i still get a notice of payment monthly,,, thought it was free,,, jimmy

Adobe have PDF services and PDF apps. Some are free, some have a one-time fee, some have a yearly or monthly subscription. So to answer your question we'd have to know exactly which "PDF service" you mean.