Step 1 7 days free course 
Step 2  Then do a mock test here, wait for the result after 5 days 
https://ielts.idp.com/thailand/about/article-academic-or-general-training
Step 3 depends on the score, if the score is >= 5, then any of our courses will help you depending on various factors. Some students study very effectively, then self-study video course should be fine. especially, you need a band 6.5 overall, which is much easier than band 7. However, if you struggle with self-study, I would suggest enrolling in the 1 on 1 guarantee course ASAP, since there are 10 seats/ month. You  need a recent test certificate or mock test result with each band >= band 5 to enroll in the 1 on 1 course. 
If your score is lower than band 5, that means you need to study grammar first. Then ONLY enroll self-study grammar course > after studying it > do a mock test again> your score should be 5 in each module. 
After that, consider video or 1 on 1 course 
Also, for reading, you need to start memorizing vocabulary. 
https://item.jd.com/11679017.html
you should be able to find a copy on Amazon as well. 
Aiming for  Listening 7 Reading 6  Writing 6.5 Speaking 7 
because you may find it veery difficult to memorize reading vocabulary but listening has less words to memorize