You are along the right lines. If it were me I would:
Do a reasonable level of research about the job, he company and the people who are interviewing.
You are right in if they ask you, then you use what you have and you emphasise your transferable skills. You might make a point of saying those skills are exactly what are needed or fit the job description and impress upon them how practical or appropriate they are. Back up every claim with an example. Dont over or under sell it.
Be confident they invited you, so from what they have seen they are interested.
Look at the job spec and conbince them you can do it. Part of it is reasonable confidence.