It’s funny: I have been thinking about doing a tutorial series.
It is difficult to gauge your background and, there is potentially a lot to learn. As with many things, I think your best bet is to dive in and try something! It’s only paper.
I mainly work in a style called origamic architecture. Though there is some fuzziness to what is included in that style, the prototypical examples are like my lunar lander in this thread: one piece of paper cut and folded but, not glued.
There is a badly-outdated origamic architecture community site with lots of links to resources (including tutorials and books) here:
http://origamicarchitecture.org/
There are other ways to do pop ups by building elements from multiple pieces of paper and gluing them together. I have limited experience with that but, it can make things easier for some designs.
Most people start by making cards from other people’s patterns to get a general feel for how things work.
There is software available that may help you get in the general vicinity of what you want and, you might be able to make changes from there. That is: make something close to what you want from block shapes. Then, refine the generated pattern from that to get what you want. Playing with the software may also help you start to think in the constrained 3D space of pop ups.
Pop-Up Card Designer Pro ( http://www.tamasoft.co.jp/craft/popupcard-pro_en/ ) is from the same person who makes some well-known pepakura software ( https://tamasoft.co.jp/pepakura-en/ ).
There was another more recent package ( http://www.popupcardstudio.com/ ) but, it looks like they may have gone under as their website is no longer working.
I mostly just work in regular vector software (Inkscape and Corel Draw, mainly).
How challenging this is also depends on how complicated you want to get. One of the keys is figuring out what details are critical to representing a given design and, which you can omit. I can see an easy version of this with three vertical planes and, a slightly more challenging version with four. Beyond that … there are some things to figure out. Generally, though, I feel like less is more. Let the silhouette do the work and, concentrate on adapting the details (like in the shield) to make it sparkle.
If I were making your design into a 90-degree open pop up, I would start by identifying which parts I want on different vertical planes. I would make a central fold line (this would typically be where a card folds in half). I would separate the planes out, offsetting them (down) from the central fold line. Each piece needs to connect to the back of the card (above the central fold) by a horizontal piece the same length as its distance below the central fold (think stairs) or, be attached to some other plane by the difference between the position of its (hypothetical) base and the base of the piece to which it is attached.
I could also see a simple twisted crest ( Spring Belles Pop Up Card , We All Have Our Demons , 180º Open Twisted Crest Origamic Architecture/Kirigami Flower Pop UP Card ) version of this that could be quite striking.
I am not sure if that helps. I’ll try to answer any questions you have.