Reproduction steps:
1. Open Unity Hub or Unity Launcher
2. Select "Learn" tab
3. Select "Getting Started", "Tutorial Projects", or "Resources"
4. Notice that Unity Hub or Launcher does not notify if there is not enough disc space before downloading and importing the Assets

Expected: User is notified that he does not have enough disc space
Actual: User is not notified that he does not have enough disc space

Notes:
1. There is no feature to select custom project or .unitypackage download directory (it will always be downloaded to Unity Cache in drive C)
2. In Unity Launcher and Hub "Learn" tab, Assets in sections "Getting Started" and "Tutorial Projects" do not display their memory size, but in section "Resources" they do