Newbie here, need some help

Hello everyone.
I'm quite new to IM and to SEO particularly and this is my first attempt at SEO.
After a lot of reading on these forums I decided to choose a niche and create a WP blog for it.
My keyword has 15k monthly local searches, and 222k overall search results.
What I've done so far is
-Get hosting and EMD
-Install WP
-Write 3 unique 300 word articles niche related
-Install various plugins such as All-in-one SEO, Google Analytics etc
-Submit my website to various SE

After about 12 hours of waiting, my site was indexed in Google. Surprisingly, in one of my keywords I'm ranked #3,#4 and #5 overall. On a side note, if someone could explain why Google shows 222k Matches yet only 3 pages, I'd be very grateful.

My question is what should I do next. Should I buy fivver gigs to rank it even better? Also I'd like to know what is the best way to start monetizing it, is it Adsense or Geo-targeted CPA offers?

I appreciate your help.

Your first port of call is to stat studying SEO strategy. Read everything you can for a while before you start link building; and don't just buy a bunch of blasts to a brand new domain without understanding the impact.

With monetisation, you should try and use multiple methods, so AdSense, CPA, Amazon, ClickBank, DropShipping, Lead-gen etc. Anything that is relevant to your niche.

Also, get an auto responder running collecting emails and maybe giving away a free ebook. You can monetise these later.

If it is a new site, hold back on the backlinking/fiverr jobs for a bit (maybe 2-4 weeks)
Work on constantly providing new content and driving visitors to your page.
Try multiple techniques and see what works best for you