Exactly what have you set up? how are you hosting the database and how are you connecting to it?
You should be able to remotely access the DB to do design work on it, but it will be better all around to take a copy down of the server, develop with it and then send the updated design back to the server for your fellow users to test.
If you use a data separation model, you can reduce the need to import data from the current copy into a new copy you are about to put up on the server. With a data separation model, you split your database into two files. One file holds the data tables and the other file contains the scripts, layouts, value lists, etc needed for the interface. This enables you to replace the interface file with new copies and not need to import any data in the process.
We set up a computer to just act as our filemaker server that has a dedicated internet connection. I am connecting through the internet via the IWP, which I thought was going to give me the access to create whatever I needed to create.
I am not a designer, just a person with database use experience and what appears to be a pretty good manual. If there is another way to get into the creation side I would love to know what it is, otherwise, other measures will need to be taken.
If you are not the designer, who is?
Filemaker isn't a ready made application, it's a tool for building that application. You should use Filemaker Pro to develop that solution, which means you or whoever will design the database should install FileMaker on a computer to which you (or whoever will design the database), have full access. After you have developed and tested the database on it, you can move a copy of the database file to the server machine where it can be opened and hosted to the web via IWP.
IWP has a number of limitations. Whoever will design your database will need to read up on the supplied documentation on web publishing if they have never done this before.