Welcome on Steemit :)
Don't worry to much about mistakes. Of course, try to avoid them, but information for you is, you can edit your post in first 30 days after publication, so you will be able to correct mistakes.
You can find more help on official http://steemit.chat/ :)
Thank you for your kind advice. Yes, I did not know how to upload image here, but I know it now. I realize I should upload image to present a topic like this . You are a big help.