I want to learn Mandarin and have some specific questions on how to start, which resources I should use and so on. The Chinese Language Stack Exchange Site is still in the commitment phase and I am looking for a place to ask my questions instead. Would this be the right place?
In short, as is, that question is not on-topic for here. linguistics.SE is for general characteristics of (multiple) languages, and maybe linguistic questions about particular ones, but certainly not about how to go about learning a particular language.
To be on-topic (for anything) tautologically a question has to be relevant to the site. Suppose you have the general question 'How do I learn Chinese?'. Ostensibly this has nothing to do with linguistics.SE. But depending on how you repackage it, you might be able to get something.
You might ask 'What are general methods for learning languages?' where the answer would be expected to be more theoretical than pedagogical, or 'Are there any tools for language learning that are specific to Asian languages (or Sino-Tibetan, or something else)?'. The idea is to package it more locally. For here it would be 'local' to mention language families, or with a more theoretical bent.
Usually Q&A sites are not the standard place for that kind of questions.
I think it would be considered off topic, also because you're asking about a specific language, and this site is not about a specific language, but about all languages.
If everyone would ask questions for all languages, it wouldn't be a Linguistics SE anymore. The question is not bad per se, it's just that I don't think it would fit here.