if you purchased from and registered with adobe, check https://helpx.adobe.com/in/download-install/kb/downloaded-older-app.html for info on how to download non-current adobe programs.
once you download, if you're having trouble finding your file(s), https://helpx.adobe.com/x-productkb/global/find-downloaded-file-app.html
if that fails AND you've (a) registered your software with adobe or (b) can provide proof of purchase, using a browser that allows popups and cookies, contact adobe support during pst business hours by clicking here and, when available, click 'chat', https://helpx.adobe.com/contact.html
for more info on adobe's 5/2019 policy on downloads, https://prodesigntools.com/adobe-limits-software-downloads.html
[moved from Installing, Updating, & Subscribing to Acrobat to Downloading, Installing, Setting Up]