TLDR: I've been offered an interview. They want me to prepare a presentation for it. The problem is the topic of the presentation: initially, I have no idea whatsoever what to say for it - it focuses on management aspects, and my work is usually more hands-on. Obviously I can research and prepare, but it's got me wondering if the fact that I have no idea means that I am unsuitable for the post, and it is unsuitable for me, so I should decline the interview?

I applied for this job because it seems quite interesting, in terms of both the line of work and my career progression. It's a permanent contract, while I'm currently on a short, fixed term contract elsewhere. It's a more senior role than my current one, so pays more and would represent real career development for me. But as it is a step up, it would be a challenge, and would involve more leadership and management than I've done before. I have led more junior team members before, but never formally been anyone's line manager, while this job would involve line managing 3 or 4 people. I never thought I would get it or even an interview, but applied because why not? I never think highly of myself, so I risk never progressing in my career because I never reach up. So I figured I'd apply, see what happens. I have other options so who cares?

I'm not 100% sure I want the job. There's obvious advantages but I'm used to, and enjoy, more hands-on work, and I'm not sure how much this would just be managing others who are doing the hands-on stuff, and I'm not sure whether that's a direction I want to go. But I figured that IF I got an interview, I could ask more about the day-to-day etc and decide whether it fit. All with the expectation that they would never offer me the job anyway.

So they have offered me an interview. They want me to prepare a presentation, which is fine, I've done that before. But the topic is on the management side of things. Initially looking at it, I have no idea whatsoever what to say. Obviously I can research it and plan it. But I'm wondering if this focus on management, and my feeling I have no idea means that I am unsuitable for this job, and that it is unsuitable for me. Therefore, I would be wasting everyone's time by attending the interview. I'm also concerned about the questions they might ask me. While it's far from the end of the world if I don't get the job, I'd rather avoid an excruciating, embarrassing half hour or so where I completely fail to give decent (any!) answers. Normally, I'd immediately have some ideas for a presentation. Is that because I'm normally applying for jobs more in my comfort zone (at a level I'm already at etc) or because they're in an area I'm more suited to (hands-on, rather than management?) Should I decline the interview?