@ Michellle. Hi, and welcome to the forum! I do not think it is either possible or wise to research all the orders in the USA… However, it is good to have some knowledge of what you want. What spirituality are you attracted to? What charisms really capture your heart? In a way, the process is like dating. Normally, it is not a good idea to simply date and marry one person. Rather, it is better to have lots of dating experience so that you can get a fair idea of what you're looking for in a spouse. As far as vocations are concerned, the attraction that comes between a person and a small pool or the "short list" is a mystery. Why do Sue and Joe get married? There are billions of other human beings! I do think with experience (either in researching orders or dating or looking at secular institutes, etc.) you tend to have a better position in which to make an informed vocational decision.
Yes, there are religious life fairs. Often they take place on college campuses (Franciscan U and Christendom College come to mind) and I have participated in one in a Newman Center where practically all the non-cloistered communities in the state (and surrounding) were represented. Ask your diocese, newman center, or a local community for more information.
@ Angelica. Welcome, too! Your first point is well made. There is a lot of prejudice about different vocations (for example, men often think that vocations to religious brotherhood are "second class" whereas the saints would disagree). I am glad that your group leader found her vocation in a secular institute. It is a beautiful vocation, but one that people often ignore because they tend to be less visible and for some reason there are priests out there who think they are "second class" for people who couldn't make the grade to religious life, so to speak. Certainly, having a solid understanding of the different vocations out there (like secular institutes) is essential for proper and informed discernment.
You asked about not approaching bishops. The reason is that it is a complete waste of time for the bishop to hear about a plan or a dream that usually does not come to fruition. The challenging part is not getting a nod from the bishop, but getting real people into life together. If established communities find it hard to find "vocations", then one person with an idea is going to have it even harder. Thus, it is best to wait to begin the dialogue with the bishop until you actually have people (not just interested but actually living a consecrated lifestyle together not in their individual homes). Then the discussion would be worth his time and attention… At the same time, though, before one starts living in common, they need to know some basic guidelines for people wishing to start religious orders– here a canon lawyer can help with advice and hopefully help the group to avoid certain headaches or disbandment.
Thanks for starting the conversation!