Never feel embarrassed about something you ventured into. Never feel dejected at knowing nothing. Everyone starts something knowing nothing; everyone starts learning one step at a time.
My venture into blogs started because of ISC - there was a program here wherein we were encouraged to (a) write about ISC at our blog and (b) promote ISC by giving links to a relevant page when answering a query at other forum based / Q&A sites (such as Yahoo answers). That is why I started a blog.
Like you, for my first blog, I simply put a mishmash of topics, with no proper definite niche. Yet, amazingly, it turned out to be getting some traffic. Gradually, I got so thrilled just to see the visitors from all over the world (I put the free Feedjit traffic feature at all my blogs for this) that I got excited. As it is, I do so love writing. So I fell head over heels in love with blogging. I did not care a jot about the earnings frankly and even today am barely getting a few cents collectively from my various blogs, but they are all close to my heart, like family members, so I do continue to post at most of them once in a while. Only the first two which I started - one a general one & one on India travels - are not getting my attention, but still getting good views.
K Mohan asks "But tell me frankly what are the uses of blogging, and what benefits one can derive from blogging. Is there in compulsory to register our blog address with any authority or the contents what we write is governed by web rules ?"
(1) The benefits of blogging is that you can use it as a platform to try out your writing skills + you can promote your ISC articles via your blog + if you spend regular time on it and it is a niche blog, you can generate good AdSense earnings too. Other than that, it gives you an adrenaline rush to, well, just nurture your blog & see people visiting, some of them even posting comments about how they liked your blog. I cannot quite explain the feeling one gets - one has to start blogging to understand what I say.
(2) Blogger.com is a free product offered by Google (don't we all love free things!!) No fees at all. Simply start your own blog. There are very user-friendly features, including any template you wish. Start here: https://www.blogger.com/about/?r=1-null_user
One of my blogs I converted into a .com website through GoDaddy, which has very nominal annual fees. I have taken the help and advice of many ISCians for my blogs either through queries posted in the Ask Expert section or via the forum or direct email communication. I would advise other fellow ISCians who have ventured into blogging to do the same - take full advantage of all that you can learn through ISC.
On a major basis, though, it has been a self-learning experience, delighting in discovering something new, such as creating a table in my blog or attaching a small video clip.
There is the cliched list of "Top 100 things to do before you die". Well, I would advise everyone to try blogging at least once in their life. Honestly, if you genuinely do like writing, you will have a whale of a time!
When people come at you with their worst, you should come at them with your best (advice given to Selena Gomez by her mother, quoted in Time magazine.)