Importing/Merging wont work. Also .uasset to content wont work

I’ve come across a bug of sorts. Or I may also just be dumb.
Okay so here’s the deal. I’m new to Unreal Engine. I want to test out building a small environment, and found some nice assets for free on the internet. I download the asset file, and it comes in a .zip. Nothing unusual. Opening the file, however, I come across… .uasset? So I google it, and everyone across the internet says its fine, just place any .uasset files in your content folder. Within the zip, there was an initial folder to open containing all the files for the assets. So i just move the entire folder into the content folder. Seems like that would be taking it safe.

I check my project in Unreal Engine, and thats where it goes bad. The first time I tried it, was with a vegetation asset. Most assets had no texture, and others just didnt even show up. I thought ‘maybe i got unlucky.’ I try another one, called ‘Red Room’, which is actually an entire project open to the public. I download it and test out merging files from that project to mine, and that works out fine. There are some problems though. Some Materials aren’t working. They are present in the content browser, however placing them on a prop takes either over 15 minutes, or never successfully textures the prop. Most materials work however. So I’ve been using this method for other projects and their assets.

Then I tried the vegetation again. I noticed that it had its own project too, so I tried the merge method, and it mostly worked. However, some grass props are untextured and completely white.(not snow, white), while others are either fine or half textured. A bit buggy.

Because of this, i’ve concluded this is a very unorthodox way of doing it. Also, everyone and their mothers on the internet are saying dropping the uassets into the content folder, or the entire (decompressed) zip file into ‘Content’ folder of my project should work perfect.

Half of the time it doesnt. With the fireplace one, there is no easily identifiable folder to drop in, so I dropped all files into my content just in case, and used content manager to search for ‘fireplace’ and found the untextured prop.

The only material for the fireplace I find, and trying to apply it ends up being infinity loop again. Never actually applying the material to the fireplace. i’m unsure what I’m doing wrong or how to fix my importing files issue.

Note: 1. Import 2. Select .uasset files doesn’t work. I’m not sure if i’m supposed to change the uasset files, either. But putting them in content folder doesn’t work. very unreliable.

Please Help!