You only deployed the site three days ago. I doubt Google would have gone out and indexed it in that short amount of time unless you specifically prompted Google to do so.
I cannot help you find a free domain on freenom. This is a process you will need to undertake yourself.
Once you have a domain I suggest reading over the Custom domains documentation and over [Support Guide] DNS Quick Start - How to set up DNS to configure it. If you have trouble in configuring the domain then by all means open a new topic and the community will happily provide assistance where possible.
I don’t believe there is any guarantee that you could have your site indexed and searchable with Google or any other search engine by 6 April.