Does The Unlicense require you to credit the original creator of the code? When I was doing research it was unclear to me.
The Unlicense is intended as a public domain dedication that allows any use without any conditions. The Unlicense is actually written a bit contradictory so it's not clear if it actually achieves this purpose in a portable manner across jurisdictions, but that has little bearing here. This leads to the following alternatives, that purely depend on copyright and contract law in your jurisdiction.
If the public domain dedication works, there no longer is any copyright for the code and the original author has no particular right to be credited. Nevertheless, I would suggest you reference the original author and keep a copy of the Unlicense as proof that you're allowed to use the code.
If the public domain dedication doesn't work, the Unlicense still allows you to “copy, modify, publish, use, compile, sell, or distribute this software”, and without any conditions. Nevertheless, I would suggest that you reference the original author and keep a copy of the Unlicense as proof that you're allowed to use the code – just treat it equivalently to the MIT license.
There is a small but non-zero chance that the Unlicense's contradictory drafting renders the entire Unlicense ineffective, in particular if an ineffective public domain dedication is inseverable from the permission to use the software. Should this be the case, you cannot use the software at all.
Furthermore, you may live in a jurisdiction that protects moral rights – the right of an author to be recognized for their work. Rules on public domain works differ here, with some countries terminating moral rights when the economic aspects of copyright end, whereas some countries recognize indefinite and inalienable moral rights (e.g. France). (For this reason, CC0 is a much better tool for public domain dedications than the Unlicense, since CC0 also contains a promise that any unwaivable moral rights will not be enforced.) So if you are in France or similar countries, you'd have to attribute the author anyway, regardless of what the license says.
What does this mean for you?
It is possible that you can just use the software without any conditions or attribution requirements, in particular if both you and the original creator are in the US.
In most cases, it's sensible to treat the Unlicense equivalently to the MIT license (keep author attribution and the Unlicense text in all copies of the software). This is useful compliance documentation for you, satisfies moral rights if they apply, and also works if the Unlicense doesn't actually work as a public domain dedication.
It is theoretically possible that the Unlicense is entirely defective so that the software cannot be used, though I'm not aware of a jurisdiction where this would be the case. (Such a jurisdiction would have to not recognize public domain dedications, consider licenses inseverable by default, and interpret licenses literally instead of following the licensor's intent.)