Instead of risking a crack, there are official ways to get AutoCAD or comparable tools for free or at a lower cost:
: If you have an active subscription, you can officially download previous versions of AutoCAD, including versions similar to 2018, directly from your Autodesk Account. Free Alternatives to AutoCAD
: Cracked versions of AutoCAD 2018 are often modified in ways that make them unstable. This can lead to frequent crashes, corrupted drawing files, and loss of work.