Nearly everyone finds the prospect of traveling across the globe to an unknown country where they don't speak the language, to embark on a physical challenge that they don't feel they are ready for, entirely on their own, to be somewhat scary! Why not, it IS scary! Your thought to connect with some traveling companions now is a reasonable reaction.......except that you don't understand the Camino.
The Frances in particular, greets four trains a day carrying fresh pilgrims, most of whom are on their own, and most of whom are just as nervous as you will be. It turns out to be simple to meet people, as early as in the airport on your way. Pilgrims are easily recognized, and all are receptive to sharing the unknown with a fellow traveler. At that time of year, there will be hundreds of people just like you, stepping off the train into the unknown.
So why not set up walking companions in advance? Easy.....you don't know how you will connect as pilgrims. Beyond personalities and motivations, there is the crucial aspect of pace to consider. You must walk the Camino at your own pace, and even you don't know what that pace will be until you set out. Over the first few days, the pilgrims walking at a common pace see each other at every break, and naturally form a community with one another. You will see these same people every day for the next month, and likely walk into the square in Santiago with some of them. Its very unlikely that you can pick these people out off the internet, and somewhat foolish to try.
Don't worry about being alone, it won't last long. Meeting people is the least of your problems. Get your equipment together, pack light, train, and worry about your shoes. These are the real concerns.
Buen Camino!