What's the difference between "target creature" and "target creature you control"?
You can pick anything matching the targeting condition.

If the targeting condition is "target creature", you can pick any creature. Period.

If the targeting condition is "target creature you control", you can pick any creature you control. Period.

If a characteristic (e.g. Green), status (e.g. Untapped), controller or owner isn't specified, it's not a factor. You could even pick a tapped creature for "Tap target creature" (even though it's impossible to tap a tapped creature) because the only part that's important when picking a target is "target creature". There is only one implicit limit to targeting: It's illegal for a spell or ability to target itself.[CR 114.5]

Keep in mind that there are many cards that add other limits. In particular, those with Shroud, Hexproof or Protection.