Hi @preetham,
I'm not familiar with this guide but it seems out of date - in particular I would avoid using the "release" zip of Boulder it instructs you to download. We don't do releases that way and it doesn't reflect what's running in production.
Instead I would recommend you follow Boulder's own quickstart guide.
The easiest check is to see if your Web Front End is able to deliver the ACME directory. If you're following the Quickstart guide I'd expect something like curl http://localhost:4000/directory to return a JSON ACME directory.
This is covered by Boulder's README in the Working with a Client section. The short answer is that you need to use an ACME client (like Certbot for example) and configure it to talk to your local Boulder instance.
Hope this helps,