Start small
One useful decision at a time.
Open a lab below to see its purpose, starting knowledge and the evidence you will produce. Begin with its README, then use the same prepare, show, analyse, check and verify commands across all twenty.
Save a prediction before opening the reference answer. Repeat with less help, solve a changed case and explain the result aloud. The practice guide includes later recall checks and a private progress record.
These are original guided learning materials at an introductory level. Reference checks validate their behaviour and supplied answers. Personal completion and explanations have not yet been assessed. This is a practice curriculum, not evidence of production experience or every skill needed in a security role.
All inputs are fictional and all tools run offline. Some labs read formats such as saved scan exports or configuration text; others use deliberately small teaching models. Each README states its limits. No live scanning, cloud account or changes to your computer's security settings are required.