The beauty of online dating is that you can be aggressive and take the first step in the introduction. Remember these people are elsewhere and you do not need to fear the introduction. This will just show that you are interested and, in general if the other person is also interested you will get a response. The response time may take time for not everyone is online 24 hours a day and there are times that the response would take days. It's something you should not feel bad. It is quite common in online dating to get no response or delayed response of the person you sent the message.
Online dating sites also generally have a way to correspond with people who want the same things you are and who have the same interest. Take advantage of this service so that people meeting would be easier for you.
When you create your profile make sure it is short but very interesting for you to attract people's attention easily. People do not want to read a novel to read your profile. Following these simple steps and adding a little of your own will surely get the results you want and the enjoyment of online dating.