https://astronomy.stackexchange.com/questions/33514/how-fast-are-we-moving-relative-to-the-cmb#33515

Earth moves with somewhere between 230-500km/s, long term average should be 370 km/s

https://en.m.wikipedia.org/wiki/Formation_and_evolution_of_the_Solar_System

https://en.m.wikipedia.org/wiki/History_of_Earth

The solar system and earth formed 4.6 billion years ago.

https://numbat.dev/?q=370+km%2Fs+*+4.6+billion+years+->+ly⏎

That means the solar system travelled 3.45-7.67 million light-years (5.67 for the average speed) since then.

That plural form (millions of light years) is borderline, but actually not incorrect.