Q: How do I unhide my number on iphone 5c?

You must be using a CDMA carrier (such as Verizon in the U.S.).

See http://support.apple.com/kb/HT4515

By the way, another thing you could do on a call-by-call basis is dial *82 before the number.

For example, if you are calling (987) 654-3210, dial *829876543210 which will display your caller ID for this call.

(I assume you're in the U.S. for this to work.)

U.S. Cellular is CDMA as shown here:

http://answers.yahoo.com/question/index?qid=20090616183536AAoCx52

That's why you don't have the Caller ID option in Settings.

There are other implications -- for example, you will not be able to be on the internet while you're on a call.

Excellent!  I hope that carrier works out well for you with the iPhone.