Need Suggestions: For Higher Keywords Ranking

Hi there!

I am posting this to get a few recommendations, but before I raise my queries, let me give you a short background and figures:

Last month after a gap of 2 months, I wrote an article while keeping in mind a highly competitive KW (kwd 60). I got a free trial of SEMrush on the 5th and saw some good number of KWs ranking for the post I wrote.

Here are the details of the top three KWs:

• Keyword 1: avg page 3 (from last one month), KWD: 59, Volume: 9k+/month, CPC: $4.50
• Keyword 2: avg page 6 (from last one month), KWD: 45, Volume 12k+/month, CPC: $2.41
• Keyword 3: avg page 7 (from last one month), KWD: 63, Volume 5k+/month, CPC: $5.68
• Collective KWs ranking for the post is 19 (within 70 pages)
• Collective monthly searches for 19 KWs: 42000

About my blog:

• One-year-old self-hosted WordPress (400 visits month since July end)
• Moved from Blogspot 3 months back (earlier traffic 4k month )
• 45 articles (handwritten in the same standard I am writing this)
• Avg. 1400 words/article
• PA: 19, DA: 22, MOZ:2, Spam:0

I am thinking of hiring drip-feed link building services from BHW to improve above KWs ranks. But as always, I have more questions within my head (username represent me perfectly):

• Is link building the only requirement? Or am I missing something?
• Shall I combine above with SM signals?
• Shall I add more related content for the internal linking of the above-said post?
• What would be the next step of an experienced SEO expert in the above situation to beat the competition?

Though there are higher chances of this thread get buried without notice, still hopeful of getting the recommendation (s).

Thanks in advance for your time and valuable feedback/solution, or even seeing this