I am a US citizen looking to move to Germany to study German and then find work to obtain a long-stay visa. I understand that I can stay up to 90 days within a 180 day period without a visa, and that I’ll need a residence permit in the form of a visa after that time. I was under the impression that I needed to apply for the Student Visa for language courses, but my intention is not to apply to a university after my language courses.
I keep seeing something about a Language Course Visa, but looking on [this page,](https://www.germany.info/us-en/service/visa/residence-visa/922288?openAccordionId=item-2435482-3-panel) there is no mention of such a visa.
Additionally, I am having a hard time discerning the difference between a residence permit and a visa. I thought they were one and the same, but according to [this Diplo page,](https://visa.diplo.de/en/index.html#/vib/schnelltest) (choosing Quick Check and then the option that includes USA) they are stated to be two different documents. What information is needed when applying for a residence permit? I am not able to find any information on that either, and I have checked the wiki several times.
Let me know if you need more info, and thank you in advance!