I'd recommend that you talk directly with someone on our Student Services team: 800.576.GMAT.
The question here really hinges on how much of a "beginner" you are. We don't assume that people have already studied before they start taking our class, no (though we do assume you do your homework every week of course!). But the teacher will have a classroom full of people to handle - he or she will not be able to pace the course at exactly the right level for just one student all of the time. There will be times, for everyone, that the class goes too fast or too slow - those times will just be different for different students. We do our best to balance, but this is inevitable as soon as you have more than 1 student at a time. :)
Take a practice test to see how you do. If you're scoring below 550 total or below 50th percentile in either quant or verbal, consider working through our Foundations of Math or Foundations of Verbal material first, before you take the course. If you do this, I'd recommend signing up for a course that starts about 4 to 8 weeks later - that way, you'll get all of the Foundations materials as part of the program. Then you'll work through one or both books (depending on what you need based on your test score).
Here are a couple of things you should know before you take that practice test:
https://www.manhattangmat.com/blog/inde ... lly-tests/http://www.manhattangmat.com/blog/index ... ould-i-do/I also recommend that you take a look through our free e-book The GMAT Uncovered. You don't need to worry much about the essay and IR details for now, but take a look at the sections on quant and verbal, as well as the section on scoring.
Let me know if you have other questions! Also, for future questions like this one, do contact our Student Services team directly. As you've just learned, this part of the forums is not manned every day, so you'll wait for a response.