"Don't pay too much attention to grammar." Breaking that rule is one of the ways my high school failed to teach much German to most of its students.
Back in the ‘50s or ‘60s, the U.S. government Foreign Service Institute put together a series of language learning courses that covered most of the popular languages at the time. They’re public domain and if you look hard enough, you can find them on the internet - they’re dated, but they’re still accurate (there are some here http://www.fsi-language-courses.net/ but the hosting sucks). I’ve learned Spanish and Frenc…
I love the endless FSI substitution drills. They feel like video games. Also the Spanish ones are done so quickly that the instructor almost trips over his own tongue.
edit: also, https://fsi-languages.yojik.eu/, well-hosted labor of love.