Tor: How do I install Tor Browser on my computer?

Short answer

Download the correct Windows, macOS, or Linux package from the Tor Project and follow its platform instructions. On Linux, extract the archive and start the supplied desktop launcher; on Windows or macOS, use the normal installer or app package. Verify the signature first if you need stronger assurance, then connect from the first-launch screen.

Sources

Tor Project: Installing, Tor Project: First launch.