Can I buy an iPhone 5c with no contract/service from Walmart or apple store?

Please let me know As soon as possible!

Yes! As always you can buy any device at apple in a unlocked fashion.

Yes I would say get it from apple so you get their one year coverage as well.
Then get the most out of your new iPhone by using solavei (see sources). They have 4Gigs of 4G/LTE data included in their unlimited everything plan which is only $49/month. A lot more high speed data than the others!