how can i delete the rental stores in scipio
Stores and other data is not supposed to be removed, as there are many dependencies data-wise that might rely on it (ie: orders, user data, catalog data etc.)
If you are still implementing a new store, I would recommend to start with an installation without the demo-data. You can export your current data, modify it and load it as “seed” (install-) data. So that your current state isn’t lost.
Using seed data makes it easier for you to reinstall the system, which is why we recommend setting it up during development.
any tutorial of it which one i have to download
Unfortunately, there are too many options for this system and there is no collection of datasets that fits all implementations (some use warehouses, others use manufacturing, others still only use the shop, and yet others use a combination of all or the CRM or CMS and so on). So there is neither a tutorial nor a list of common entities available. We do have a few templates for exporting the catalog however and a special application just for CMS exports.