I am not highly experienced with Resonite or it's former platform, I am learning as I go as well, it's going to be a little bare-bones for now until I continue updating this.

First things first: If you are/were a VRChat player in any capacity, do not go into this thinking it's going to be anything like VRC you will be severely disappointed. While both are definitely built on similar concepts, both are completely different executions. Resonite has much more of a focus on creation and user freedom. It's systems are complex and will take time to get used to, especially if you're used to other social VR games such as VRChat.

If you need a better idea, people often describe Resonite as like a VR Garry's Mod or SecondLife.

This one was probably the biggest curveball I faced because if you're used to literally any other platform ever, you think you'd just click your profile picture and it'll bring up a file browser.... and then get confused when nothing happens. The way you actually goes about this makes sense in terms of consistency.

• First go into the "Files" tab of your menu, find the image you want as your pfp on your computer and spawn it as an image/texture.
  
• Then grab that image once it spawns, go to the "Home" tab in your menu and click your icon in the top-left corner, drag your image onto it and click it.

To add a custom thumbnail to your item, open the root of your item in your inspector (Not CenteredRoot, the model name) then click "Attach Component", under "Uncategorized" and find "ItemTextureThumbnailSource", add it and then scroll to the very bottom of your root, spawn an image, and drag it into the "Texture" slot of the ItemTextureThumbnailSource component, then once you save the item into your inventory, it'll have an icon!