I’m only just learning and wondering is this is something i should worry about and fix before I proceed.
Nope, this is usually a very benign message. There are some cases where it can become a problem in a much more established project with lots of prefabs or customized import options, but if you’re just getting started, not much to worry about.
The most likely cause of this error is if you go into your file folders and delete a .meta file, and then go back and try to import the asset from its original package again. Whenever a .meta file is missing, Unity will invent a brand new one for its own purposes, but that won’t match the asset that came in the package. Generally, don’t delete or rename or move files that are in your Asset folder, except by using Unity’s Project tab to do so, and you won’t run into this error message (or its complications) again.
No, that’s not correct. You are getting that message because the Folder ‘Scenes’ already exists in your project, and was going to be overridden with the one you are importing. This is fine in your case. Folders are fine, but if it dose that on a texture or game object, or animation, you WILL loose the original file, and it will be replaced with the one you imported.
Example of this not being good is if you import a character you bought on the asset store, then import another character (always happens when both character’s are bought from the same user), your second character may share texture and animation names, but are different textures and animations. Last character imported works fine, but the first one is now very broken. All the textures will be messed up and the animations will be wrong.
Unity needs the option of “Import as new” where it imports a new asset with a unique name/ID without overriding any existing objects.