You can directly from the official Steinberg website to get a professional-grade music notation software for free.
Dorico SE is an entry-level version of Steinberg's advanced notation software, designed specifically for students, teachers, and beginners. It offers many of the same core features as the professional version but is tailored for smaller projects with a focus on ease of use. Key Features of Dorico SE Compare the Versions of Dorico: Elements & Pro - Steinberg