I have an acoustic guitar with a jack port at the bottom. I have a cable to go from the guitar to my laptop USB. What else do I need to record myself.
That should do it. So the cable in the middle is really an adapter. What is it? What’s it’s name or model? Some of those are really microphone adapters and they won’t like the guitar very much.
Koz
If everything is OK, you can do overdubbing, too. Play to yourself several times or a backing track. How well you can do that depends on the first answer, above.
Koz
Select the USB device as your [u]Recording Device[/u]. (And make sure it’s NOT selected as your playback device. 
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So you may or may not have have an amplifier built into the guitar. For an “acoustic guitar” there will be a pickup microphone. If you also have volume and tone controls and a battery on the guitar, it will be sending out a “line level” signal which can be used by a good USB A-to-D converter. If you have no battery, there is no internal amplifier and you will need a guitar amp. Fortunately, there are a few USB devices which accept “guitar” inputs. Make sure your USB device has a “guitar” input.
I don’t know, a microphone? So just because the cable end “look” correct, doesn’t mean it is electronically correct. If there isn’t a least some kind of bulge in the cable, then it is very unlikely to have the requisite A-to-D converter. Where did you get the cable? Is there a brand/part number on it?
I suspect you are going to end up with something like the Behringer U-Phoria UM2 USB Audio Interface which has a built-in guitar amplifier. Hey, it also has a microphone port!
I hope this helps. 