There are two big areas of difference between the successful sample print and the model you're failing to print: geometry and how it's sliced.
First, geometry. The sample print looks detailed, but if you actually think about it, each cross section until you get to the ears at the very top is just a single, mostly smooth loop, whose shape differs very subtly from one layer to the next. (And indeed, when you get to the ears, it doesn't look good anymore - there's bad stringing from missing or wrong retraction.) This is the easiest type of object to 3D print, and there's a reason they chose it as the sample - it's hard to get wrong, and it looks nice.
The tabletop mini style figure, on the other hand, has a lot of (very small!) disconnected components in each cross section once you get past the base. Printing these accurately (or even successfully at all) requires your printer to be able to stop the extrusion, move the print head to a different location, and resume extrusion there, without losing material to oozing on the way or skipping/jamming when it restarts. This is perfectly doable to an Ender 3, but it requires good instructions from the slicer.
That's where we get to the next part of what's different: slicing. The sample print was sliced for you with Creality's preferred options to show off the printer's capabilities (and they didn't do a very good job at that - see the stringing at the top, which a properly sliced print on an Ender 3 should not have). Yours you sliced yourself, with whatever profile came with Cura. Even if the stock slicing profile they provide is fairly good, this is a really difficult print (see geometry above) and will require a good bit of work to figure out how to print it successfully. It probably needs some supports, and needs retraction tuned well, and probably needs combing limited.
I could go into details for how to go about finding the right options for this print, but I think you really need to start with something much simpler. I know I did the same kind of thing (looking for fancy models and trying them) when I first got my Ender 3, but it ended up being frustrating and took a lot longer to figure out what I was doing wrong than it would have if I started out with things like boring cylinders or calibration cubes. Start really simple. That way you can get to know how the slicer works, what options are available and how they affect what the printer does, and most importantly do an overall sanity check that it's slicing right for your printer. (Cura used to have a bug where it always wanted to reset to the wrong filament diameter, 2.85 rather than 1.75, which gave extremely underextruded prints, and parts of your failure look like that may be what happened, but I doubt it is since I think that behavior was fixed a couple years ago.)
In slicing and printing some simple test pieces, you'll probably find you have questions about what's not going the way you expect. Ask those. Then, once you get the problems worked out, start trying more elaborate prints, and ask more questions when you run into problems with them. After getting past very basic checks, a good next stage would be "nontrivial objects that don't need supports".
