No KW tool predicts accurate competition. For a 50K keyword, you'll need a shit ton of money to rank. Find smaller keywords 50 - 300 SV per month and write more content.
Can you explain to me how ranking works or is it too much too explain
Read the forum for 3 - 4 months and you'll get it. It's impossible to explain otherwise, there are too many moving parts.
I am not a professional, but my response is:Can you explain to me how ranking works or is it too much too explain
What factores do we have that influence the ranking?
Backlinks and what other stuff
You can get 30 days free membership of semrush using BHW so I would suggest checking there
Look for this guy's posts @RealDaddy - He also has an e-book for sale in the marketplace that can get you started on KW research.