If you're having trouble finding something you're looking for, you may have better luck if you put your search term into Google Translate and translate it to Japanese.

(A large portion of the CSP userbase is Japanese! These creators makes a lot of assets and not all of them are tagged with English tags). Once you download your model, it'll show up in the Download folder of your Materials palette. From there you can move it to your 3D folder or add it to your favorites so you don't lose it. If you want to go a step beyond and add your own model to CSP, you can do that really easily. I'm not a 3D artist and I don't have any skills with making my own models, but thankfully there are plenty of resources online where you can buy or download models to use. One place I like to find models is Sketchfab. They have a marketplace of both free and paid models that you can use (just make sure you check the licensing before downloading!). Here I'm using a medieval cage asset from Sketchfab. After checking the license, click Download 3D Model to see the file formats you can download. For Clip Studio Paint, we want to use object files (.obj).

obj format, there are mesh converters online you can upload other formats to to convert it to.

When your file is downloaded, extract the. Obj file somewhere you won't lose it (I recommend making a folder for all your models somewhere on your computer).

Free 3d models for clip studio paint