Steps with the help of which you can increase DA of your website:-

1. Work on your On-Page Optimization:- Optimize your content, image, videos, and other media elements on your website. Try to use keywords naturally in your content and also add internal links to your content.........

2. Work On Off-Page Optimization:- Make backlinks on high authority websites. Also, make backlinks on the related websites. Avoid making bad links. Try reaching out to other webmasters let them know that you exist..........

3. Work On your Technical SEO:- Once you get your technical SEO correct in the beginning then you don't have to deal with it again. For this, you should register your website with Google Search Console and Bing Webmaster tools..........

4. Make Your Website Mobile Friendly:- Mobile searches are more than desktop. It is a ranking factor. Google is working on a mobile-first index and websites that are not mobile-friendly will not be included..........

5. Improve Your Page Speed:- If your website loads faster, it will not only helps you to improve your website ranking but also make the user experience better, this means more sales, signups, and leads.

You can build quality backlinks by following ways:- 1.duplicate competitors' best backlinks. 2.analyze competitors mentions. 3.You should build backlinks from infographic. 4.Do more and more guest blogging. 5.Buil a great internal structure. 6.Reachout and advertise your best content everywhere. 7.Do broken link building i.e. finding 404 error in blogger's website and informing them about it. It may take time but it worth it. Hope this is helpful.