In a faculty interview, when asked about how to prepare for lab equipments and how to search for funding, how to answer, esp for postdocs having no experience in these things? This is spoken in a context of an engineering deparmtent whereas I do theory work only.
Fortunately, as a post-doc you should have access to two people to discuss this with. The first would be your PhD advisor, and the second your post-doc advisor. In most cases (yes, this SE gets many bad stories, but there are many more good endings), these people will want to help you continue in your career.
You PhD advisor is a professor, so went through this exact kind of interview at some point, and has likely seen it from the hiring side as well. If your post-doc is at a university, well, you get a second view of that process. If your post-doc is in industry or a national lab, it is highly likely that they either applied for tenure track positions at some point, have friends who did so, or have had other post-docs do so. Further, to get their positions they went through a slightly different interview process, but that still sheds light on how to approach an interview in general.
I have always been interested in helping anyone who worked for me to fulfill their goals. Perhaps they don't work for me anymore, but they are 'my' people forever.
Look...these people are hiring you to do these things. As a natural scientist PI, you will be the leader of a group of people and have significant responsibilities (getting $$$ funding, using it, managing people, etc.) It isn't quite as bad as running a company since you have a lot of systems to rely on (e.g. department's accountant). But it is a real position of leadership.
The department is aware you are not a served PI. But they are expecting you to get it done. Go research it. Have some interviews (make a list of questions, make a list of people to talk to*), develop a set of insights from the interview work stream, form a plan. Obviously as you execute the plan, you will learn more (no battle plan survives contact with the enemy), but the act of planning will make you more likely to succeed and learn while executing.
The interview question is completely reasonable. If you want to be the next Sean McVay, you need to show that you have put some effort into thinking about how you will run things as head coach. They know it is a step up. But they want to see that you WILL step up. You're not a student any more.
Personally, that you haven't researched already or that you have to have an Internet Q&A tell you the obvious "go figure it out" is a ding for me. Now if you HAD researched it and made some targeted questions that would be good.
Edit: Oh and the "lab equipment". Ai yi yi! You ABSOLUTELY need to have a plan for what equipment you need/want, how much it costs and how to get it. Heck, at a good R1 school, they compete for you (as a top candidate) based on how many hundreds of thousands of dollars your startup package is. If you don't know what equipment you need, how the heck are you going to have a working lab set up? Figure out what area of research you will do and what is needed to do it. I wouldn't exactly hand them a bill (wait until you get two offers to play some negotiation upwards games), but realistically, you need to make a plan for how to set up your lab. What do you need and what will it cost? This includes things like fume hoods or special utilities (gases, 3phase power, etc.) that may need to be installed for you, not just benchtop equipment.
*Advisor, department chair, department accountant, and recent person who got hired. Can look at both current place and where you did your grad degree. But before you talk to them (a) make a list of questions (modify and change it as you run the interviews--you will find some new questions and not need to ask other ones--this is information gathering, not a marketing survey); (b) have already done the personal work (as best you can) to develop a research plan (what area of work; what types of experiments; what are the needs in equipment, manpower, $$; what is the time phasing (e.g. building apparatus).
In addition to user Jon Custer's suggestion, I advise that you be honest about your abilities. Faking it will possibly be noticed and will possibly come back to bite you later. You are better to say that "I have a lot to learn about those" than to try to sound like you have a skill that you don't.
If the application is to a large department then there will likely be opportunity to learn from other colleagues and this will be noted. It may be more critical for very small departments where the skills of individuals are more critical, not being shared.
You can also speak about a "plan for learning" how to do the things that will be expected of you but that you don't yet have the experience for.