If you are familiar with Lupin's history in Anime, you have most probably seen "The Castle of Cagliostro" (1979). If not, I would watch that highly rated older movie first as an introduction to the characters.
This new Lupin movie from 2019 (released in Japan in late 2019, the Covid epidemic, unfortunately, prevented a wide cinematic release in many countries in 2020) almost rates as high in my opinion; the 3D animation quality, in particular, is fantastic.
The story/plot is somewhat predictable and (especially) the last third shares some parallels with the third Indiana Jones movie. That's not a major issue in my opinion (the third movie was released back in 1989, most movie viewers won't remember details).
It's a fun and fast-paced kids' (especially suited for older kids and teens) movie that adults can enjoy as well.
I would rate it at least 7+/10 and add an extra star for the excellent 3D / CG animation quality, 8+/10 stars in total.