Ensuring your hardware can handle the software is the first step to a smooth experience. AutoCAD 2019 is primarily a single-threaded application, meaning it benefits most from high CPU clock speeds rather than many cores.
Autodesk no longer sells new licenses for AutoCAD 2019, as it is an older version. However, you can still download it if you have a valid subscription (including an active maintenance plan or a previous standalone license key) or if you are downloading a free 30-day trial (if still available via their archives). how to download autocad 2019