Regarding mentors, you're going to have a hard time finding people that are going to do that for free, everyone here's got a price and if they're not interested in what you're doing you're going to be ignored. My suggestion to you if you want to become successful as a blogger, you need to find your platform. Either create your own website or join in one where they do articles like LinkedIn or Medium or if you want, maybe start here creating your own topics and posting it here, make sure that it's not just a wall of text when you're writing here, mind the spacing, margin and how you cut your paragraphs.
Seeing the topic of this thread, that is what I expected to see in the content of the Op but I see something different. I wonder why he wanted to use third party sites and still thinking of getting noticed. Medium, Reddit and some other top blogs already occupied with experience and talented writers and starting as an amateur with less experience will hardly allow you to shine especially with poor writing skills. Creating your own site if you can and make it catch attention of the visitors. And by the way, what happens to Bitcointalk Forum where bitcoin issue is being discussed? Why not start your journey here if you have ideas to share that'll benefit the community?
In the sites you mentioned, one needs to have built up a circle in order for their post to reach larger number of people either with following, karma or any sort of engagement but in this forum, it doesn't matter if you just create your account today before people can see your post and follow up with the discussion. You don't need followers before your post can get notice by different categories of people irrespective of their ranks.
Just follow the wave, people always like when it comes to making money online and exaggerated title, no need to bring quality or technical discussion. You can only attract small amount people if you talk about technical stuff, while you can gather a lot people if you talk about making money and paraphrase from other contents.
A successful blogger is when you can attract the crowd and make money isn't?
But is that how it is supposed to be? Absolutely No! Most bloggers nowadays value the traffic generated than providing accurate, authentic and reliable information. And did you just say paraphrasing from other content? Oh my God! That's against the ethics of journalism but unfortunately nobody cares anymore because there's no penalty. I personally don't engage with sites found of doing that and that act will probably ruin the reputation of the site. Just try to be unique as best as you can and you'll see how busy your site will be with people who value to have reliable information.