@Nandy B. to @Bill Plymouth 's point, you gotta get started and test different scripts. There a ton of scripts out there, wether it is online...at the end of the day, a script is guide for you not to get stumbled on POINTS you would like to hit during a CONVERSATION.
I highlight "points" and "conversation" because the two go hand in hand together. You need to have a direct objective of why you are calling them , the second most important point is creating a real genuine conversation which is often the challenge with marketers, who have their own agenda and their own agenda only and fail to do the most important thing is LISTEN and allow space for a conversation to be created. With that being said you need to know what information you need to know and be genuine enough to know that they are talking to a person who a) knows what they are talking about b) is not a marketer simply wasting their time. It's definitely an art that can be mastered from numerous calls and from some guidance from those who have done it in the past. But remember the mind frame is always "what's in it for them".
Otherwise the most overlooked skilled these days is communication, reading books such as "Splitting the difference" "pitch anything".."crucial conversations", Grant Cardone material (which we use in-house Grant Cardone University) , Keller Williams Scripts....there's just an abundance of stuff out there that will not only help you in your real estate career but also as a family, friend, employee, spouse or leader in your community. Communication skills should be a long lifetime commitment :)
P.S. for seller financing you can get a broker to send you seller financing searches and again pitch seller financing as an option that you would consider to attempt doing, and make sure you educated the seller in layman terms what seller financing looks like, people can't accept something they don't understand.