If using a rotating hard disk, then Mac OS Extended (Journaled).
Unless you want to encrypted your data, then Mac OS Extended (Journaled, Encrypted). But you can always Encrypt (or Decypt) later via System Preferences -> Security -> FileVault.
Do NOT use case-sensitive unless it is a data disk (not a boot disk), and you absolutely know exactly why you need case-sensitive.
NOTE: You cannot be using Yosemite, if you have APFS as an option. That was only available on High Sierra and Mojave. If you let us know what macOS version you are using, we can arrange to have this thread moved to the correct macOS forum.
And speaking of APFS, if you are using an SSD (Solid State Disk), then the default file system is APFS. And again the Encrypted version if you want your data encrypted.