The goal is always to have good (if not perfect) grammar and speak correctly.  However, if you ''wait until I can say it correctly'' you will never learn to say it correctly.  You must just jump in and not be afraid to make mistakes, there is no other way to learn.  

Even in a professional setting, if you politely explain that you are still learning and apologize in advance for any mistakes, I find that people are in general very kind and patient.  This may be less true if you are trying to speak English as native speakers make assumptions that everyone else speaks English (or should).  But I've had very good experiences trying to use my less than perfect German in a professional setting, for example.  

Personally I feel that pronunciation is more important than grammar, at least when first learning a language.  I have been in language schools with plenty of fellow students who had wonderful grammar, but their pronunciation was so poor that no one could understand them.  For simply trying to pass an official exam (I did this with Spanish and Italian), grammar and vocabulary is more important.  For actually using the language in the real world, pronunciation (and willingness to make mistakes in order to learn) is more important. 

Emily thanks to advise us. really it encouranges me :)

yes i agree you. but i focus grammar ,my pronouncation is bad  when i  speak

For example i want to take ielts exam. grammar is more  important  than pronouncation or unlike?

I think you should at least try. Of course we'll all make mistakes in a new language, but deciding that grammar is not very important (and therefore ignoring grammar) will certainly make the learning process longer and more difficult.