Hi Htoo Htoo, welcome to Steemit. Perhaps you have a lot of questions about it and the easiest way to get accurate answer is from reading the Official website FAQ: (https://steemit.com/faq.html).
Focus on writing a good content first, eventually the income will follow from it.
Have fun exploring and posting your experiences in Steemit. Cheers!
Thanks for your advise.Have a good day.