Is your website new. Do you have adequate keyword saturation on your website?

This is a forum - we discuss SEO related questions here. We don't do homeworks and research on demand.

You have to post photos or video with trends

I think you can put your website in the google search console there you can send requests to google for indexing, If everything will be good on your pages then Google may...

According to me TTFB is good

Actually, Its some url open with .html/without html/ with slash & without slash. Is it good? Keep your website consistent - either use .html or not. Trailing slash do...

No correlation there. Focus on what really matters. The core. Pixel length of a page means nothing, unless it causes bad user experience.

This is just one factor that you analyze. It is impossible to answer this question unequivocally.

Thanks @ravi, The same concern for a 1-year-old e-commerce site that is made on Magento. Product URL path: https://www.website.com/category/sub-category/starting-at-rs-9...

First, use google and read about it yourself. A good backlink is thematically related to the linked page and then it generates traffic to the page.