Online is often a difficult way to meet people and feel comfortable with them and there are so many inherent dangers in meeting people off the internet that it can be almost impossible to build the right level of trust.

You may find better success if you use the internet to find out locations and times of munches and parties and events in your area. Go to these and meet people there and let it be known in those circles that you are looking for a sub. Eventually something will come up. You don't even have to be worried about going alone to these places. Usually one of the organisers will help you out by introducing you to people and making sure you get involved in things.