Google Search Console - Issues with Indexing pages

Hi everyone!
I have some problems with GSC, actually, not every of my pages are indexed. I just want to know, do I need to request indexing every time I publish a new post or this will happen without my action needed? I have sitemaps already added.
And also some posts are not indexed and the reason is that there is already similar page on Google... and down below is mentioned my homepage as a result. Did this happened to anyone before or do you know how to fix this?
I'd appreciate every advice, tips, help related to GSC. It's starting to confuse me!!!

Depends on age of your site

I find new sites it is harder to get indexed even when requested manually.

Sounds like your issue is duplicate content?

blogmarketer said:

Depends on age of your site

I find new sites it is harder to get indexed even when requested manually.

Sounds like your issue is duplicate content?

Click to expand...

It's new website, so there's nothing I can do about it?

Yes, correct. And it say that duplicate content is my homepage and on the homepage I only have that post in blurb module with 300 characters excerpt. Is it possible reason?

If you can get your site google news approved it will be auto indexed as google (news) monitors for your blog feed for any new post.