[Moderator moved from Dreamweaver to Download & Install.]
First you need to ensure your device meets the minimum CPU & GPU requirements. Most Creative Cloud apps work on: Windows 10 versions 21H1, 20H2, 2004, and 1909 (LTSB branches are not supported) macOS 12 (Monterey), macOS 11 (Big Sur), macOS 10.16 or 10.15 (Catalina) - https://helpx.adobe.com/creative-cloud/system-requirements.html
From the time you download it, you usually have 7 days to use the free trial. But reinstalling your basic operating system may have caused the trial to terminate early. Please refer to this help article for more details.