Domain authority & PA is based on a lot of factors. Primarily, however, these are link profile factors such as how many backward links are pointing to your website and how authoritative those sites are.
Deep Linking: When you are building an authoritative website, make sure that all the inner pages of your blog/website are strongly built to each other.
Link diversity: It is a SEO term which is used to decide the range of different links pointing to your website.
Quality Content: You know the fact that a website should contain high quality content to rank up in Google.Create lots of linkable content.
Social Sharing: If your website actively participating in social media platforms like Twitter, Stumble Upon, Reddit, Pinterest, Facebook and etc, Google surely shoots up your website to top 10 rankings of first page.
Domain Age: You cannot expect a one month old site to get a high domain authority rank just like that. The Domain Authority of a website can depend on its age and popularity.
Get rid of bad links, Gain good links.
And Forget about Page it's not matter now, it is increasing now.