Mahdi, there are tons of resources online. When it comes to IELTS (or any exam) familiarity with the content is always important. Look for sample questions online and practice them (maybe even record your answers). Make sure you practice all of your skills (speaking, writing, listening, reading), often people focus only on writing and speaking and underestimate how tricky the other two can be.
Also, if you don't find a language partner to help you I would strongly recommend that you find a tutor who is familiar with the IELTS exam, as talking to someone who is familiar with the requirements can make the world of difference.