After creating the distribution network when I am going to access through the Domain name URL, it's showing the error '#AccessDenied'' (Screenshot is attached).

Bucket permissions. Check the Access for CDN you have created. Try to access the files with S3 URL first, if this works then CDN domain should work also

Could be DNS related, give it a few hours to update the DNS records. You can validate that by making a test file in S3 public and then try accessing it through CDN URL

It is clearly a permission issue. Either you grant public read access or use role to grant permission

Simple... You need to go to the S3 bucket policies and mention it to allow access to CloudFront. Till you do that CF can't access your bucket.... And in CF you need to give S3 as origin... It's called OAI... Read OAI and S3 bucket policies and you are gold

Do it make public

Could you share your S3 bucket Policy settings? So anyone can have a look and help you sort it out.

Never give public read access to you S3 bucket

Been long now u should be able to access the S3 content without changing any bucket policy

It seems your origins configuration is not correct. Make sure you are pointing to index.html in correct path

cloud front is not able to access the s3 bucket contents you need to check bucket policy allows your CDN to access this bucket .