Hello, ChakramGirl8, I would like to take a moment to say welcome to the forums and welcome to the Roleplaying section.
Now with the pleasantries out of the way, I would like to help you a little. Typically speaking, your roleplay won't garner much attention as is. Most people who join roleplays do so because either the plot or concept pique their interest. If you want to attract more people to your roleplay, then you'll need to find a way to catch their interest, especially considering Kingdom Heart roleplays are a dime a dozen on this site. An "alternate universe" is simply unlikely to do so without a sturdy plot to support it.
Most commonly with canon roleplays, the roleplay creator will take the work, in this case Kingdom Hearts, and add an original element to it that will set it apart from other roleplays on the same subject. This element could be an original plot, an introduction of new enemies, or even a radical overhaul of the original concept, anything that gives the roleplay the person's own, unique spin on the story. For example, my Kingdom Hearts roleplay is set ten years after the fall of Xehanort where the worlds are under the rule of a powerful tyrant known as the Eclipse King and Keyblade wielders are forced into hiding to avoid being killed by the Eclipse King. That, among other things, makes my roleplay unique and makes it more likely to attract attention and pique interest than, say, a really basic roleplay with little to no original elements added to it.
Also, you need to also put forward some ideas of your own. It's alright for people to blend their ideas together to form a roleplay, some of the best roleplays are made that way, but not many people will put forward their ideas if the roleplay creator doesn't put forward any of their own. It simply doesn't work that way. Ideas are the roleplaying section's elixir of life. They build characters, drive stories, they even create great universes for the story to unfold in. They are the building blocks of a roleplay. So, in both roleplaying and concept building, you'll want at least some general ideas for your roleplay to garner even the slightest attention. A single idea, even an off-the-wall idea, can serve as the cornerstone of a great story and a great roleplay. Look at Kingdom Hearts: originally an idea for a Disney/Square crossover, the story and concept eventually evolved into what it is today. And a great idea will (normally) attract people like moths to a flame.
So anyways, please don't take any of this the wrong way, as I wrote it all with the intention of helping you. Roleplaying is truly a great and unique experience and it is so rewarding to see an idea you thought of be played out and built upon by yourself and other roleplayers. It's an experience that any avid roleplayer would want to share and spread to as many people as they could possibly can. As such, I want to help you (as well as anyone else) to be able to enjoy roleplaying to their absolute fullest as much as I do, and being able to attract attention to your roleplay is one of the steps to doing so (unless you simply prefer joining other people's roleplays). Too many times have I seen someone try to start a roleplay in the roleplaying section and then never return when their roleplay is passed over for being too plain. I would hate to see that happen again.
Anyways, I figure I've rambled on long enough. If you have any questions, don't hesitate to ask either myself, Orion, Takushi Rena, or any member of the "SMARTYPANTS" (a list of which can be found in the Roleplaying section's Rules and Guidelines thread stickied in this section), as we would be more than happy to help you. Also, on that note, you can look through the
Roleplaying Rules and Guidelines thread for information concerning the roleplay section and its rules or any roleplaying terms you may come across. So, welcome to the roleplaying community and I hope you are able to enjoy yourself here.