Idol in My Living Room S1

Since this was made for Korean learners, it's no surprise that this is great from a language perspective. Common grammar, everyday vocabulary, and Korean subtitles means this is probably one of the easiest shows for learners, so if you want a stepping stone between language learning materials and native content, this is an excellent choice.

As for entertainment, I think it will depend on how much you enjoy the generic K-drama romance. With ten 10-minute episodes, it is much shorter than your average drama, but it packs in lots of the same tropes. So if you're a fan of the genre, I'm sure you'll enjoy this, but if not, it's still worth your time if you can't find anything of a similar level to watch.

Personally, I did find it rather boring, so I had to watch at 1.5x speed. I wouldn't suggest that unless you're already comfortable with the language at this level, though.

One of the easiest shows I've seen

This show was produced by the King Sejeong Institute Foundation, and it's one of the easiest webdramas I've seen. It's about everyday topics and the dialogue is quite simple.