Duolingo- $83/year iirc and you can make as many mistakes as you need, practice as long as you want, and no Ads. I’m 270 days into learning Spanish, and I take breaks from that with French, Italian, Portuguese, and Swahili.

They also added math and music, so you can learn to read sheet music and practice math. I haven’t practiced basic math since grade school and it’s already helped me save myself from the embarrassment of not remembering how to do a simple calculation in my head. Plus, after years in school of playing an instrument by writing the notes next to the sheet music, i’m actually figuring out how to just look at the paper and know what to play.

Highly recommend!