Well, it's a good start! At least you did try, and it's good to hear that you want to learn more. Everyone here should be able to help you. You can use Language School to ask more specific topics or just continue posting here.
Some notes on your writing:
hai my name is Luliana.
Hai is in Indonesian. English is Hi (without "a").
I want to learn about english language.
English itself already refers to the language, so you don't need to write "English language". Just "English" is OK.
But the problem is i haven't many vocabulary about english.
In formal writing, haven't is only used to abbreviate "have not" as in Present Perfect tenxe (e.g. I haven't eaten all day). If you mean "don't have", you shouldn't write "haven't". But, in informal use, you may use "haven't" to refer to "don't have".
Sorry if my language so awful.
You miss "is"

the correct one should be "...language
is so awful".
Don't forget to write "I" in uppercase. People all around the world can do it.
I know sometimes it's difficult to start learning foreign languages, but just keep trying and eventually you'll be able to learn it.