My English is very basic, so can I still learn English with

Yes, but it will be a bit more challenging at first, especially if you are trying to work with teachers who don't speak your language at all.  You may have a better experience if you find a teacher who has at least a basic knowledge of your language, mainly for coordinating logistics.  Students with at least an intermediate level of English have more options because they have an easier time communicating with more teachers, and they can understand more of the written English on the site.  On the other hand, we've also seen cases where students and teachers work together by relying on translation software such as Google Tranlate combined with our chat or messaging features.  It depends how much effort you are willing to put into it.