If you see a website offering a specific "Canva Sans.ttf" file, it is safest to assume it is a malware risk or a renamed facsimile. Instead, leverage the official tools: use Google Fonts to download free alternatives for your desktop, and if you are a Canva Pro user, upload those alternatives directly into the Canva interface using the Brand Kit. This hybrid approach gives you the look and feel of Canva's modern aesthetic without violating any laws.
You can also download Canva Sans font from third-party font websites, such as Font Squirrel or DaFont. However, be cautious when downloading fonts from third-party websites, as they may not be officially supported or updated.
