I'm starting with SVN and I don't fully understanding yet.
I installed Subversion and then I created a local repository with TortoiseSVN. I've then imported a few projects to the SVN repository but I have no idea where are those files locally stored?
Any idea where else I could look?
The repository itself on the source control server does not store the files in the same folder structure that you are familiar with. Subversion has its own unique database structure, which is what you're seeing in the repository folder.
In order to work with the source controlled files, you need to check out the repository to a working copy elsewhere on your machine. The repository itself doesn't get edited directly, you check out your code to your working copy, make changes, and then check it back in. Subversion then maintains the change history in its database as a series of differences.
It might be easier to get your head around if you consider that most people will have their repository on a Subversion server, and their working copy on their local machine.