That elearning suite version is now very old. It came with Captivate 6 and (if memory serves) the first version of Captivate that was able to output to HTML5 was version 6.1, which you might be fortunate enough to have, but you should check in the About Captivate section of the Help menu. If you do not see HTML as one of the options on the Publish dialog then it would appear that you cannot publish to HTML5 with your current version of the app and you would need to purchase a license or subscription for the current Captivate version (2019) in order to be able to publish to HTML5.
Publishing a PPT to HTML5 will usually mean that some things (e.g. animations) done in PowerPoint do not carry across to the new format. When importing a PPT deck into Captivate each PPT slide becomes a more or less static background graphic for the Captivate slide.
I am sad because it is not available.
Please consider a subscription license instead of a perpetual license... Captivate has indeed come a long way for HTML5 output, and moreover you'll find tons of new features in the most recent release which is 11.5.
Is trial installation of the latest version possible?
Same as has always been the case: you can download a 30-day trial version, but only for the most recent version. Published courses with a trial version will expire after 30 days as well.