I am unclear what you purchased. The simple way to do this is use a USB wifi nic and then a long USB cable, I think 15ft is max, to connect to your pc.
If what want is to say take a signal in and then re transmit a wifi signal say to your phone it is much more complex. This is a repeater or extender. It is generally a stand alone box.
You can easily build your own but the details sometime depend on how the system you want to connect to works. For example if you are using a wifi source that requires you to log into some kind of id.
The method that will give you the most flexibility to connect to different systems and good perforamce is to use a outdoor bridge connected to a indoor router. You can get bridge devices from companies like ubiquiti or engenius. Some consumer brands like linksys etc are selling them too now. These devices tend to have directional antenna that you can point at the source. You then connect them via ethernet cable to a inexpensive router in the rv.