Hi @hs.oliveira, welcome to the forum!
Our import feature is something we are constantly improving on, but with many different standards between popular applications we are doing the best we can to support as many as possible. We recently added full support for Google Keep import with name, content, colors and tags retained. We do not support Obsidian inline tag recognition at the moment, only content and links between Obsidian markdown files are preserved.
That being said we do not recommend importing an entire Obsidian database as the structure is often very different than a Supernotes library of cards. It might be a bit tedious but manually importing, revisiting and re-writing your notes as Supernotes cards will make your knowledge a lot more modular and flexible. Here’s a helpful article, with a list of best practices for importing.
You can currently export all your cards as markdown files, but metadata is not preserved at the moment. You could use the API to do this now but it’s not the most user friendly. We will be adding a json export in the next minor release which will give you the all the metadata and note information in one file.