@The O.P, I used to be a lot more anxious around everyone too. The only difference is that I felt free to express myself online since I could always ignore people that I didn't want to talk to block them from mean comments, harassing me, etc...

Anyways, there are lots of sites on here that offer great advice on how to talk to people online, on dating sites, and in person. Look them up. Youtube has lots of good channels for that. Also, there are a lot of self help books out there. They helped me out a lot.

Just keep things short and sweet. If you think a woman is pretty, tell her that you think that she's pretty and that you like her profile. Look for things that you have in common with the other person. If they like movies for example, talk about movies and ask them more about what movies or music they like.

Most people love to talk about themselves, so asking them about stuff that's not personal at first can help break the ice. Definitely avoid talking about anything to deep, religion, sex, and politics until you really get to know them! Oh, and if they have a pic of their pet in their profile, ask about their pets or kids if they're a single mom.

I can't think of anyone who won't talk about what they love! If they respond back to you, great, if not, move on and never send more than one message at a time as sending more than one PM at once might make you look desperate. And never talk about yourself to much. That is a real turn off.

I hope that I was able to help you out a bit. Remember, compliment, find some common ground, and ask them questions about what they like. You WILL get some responses after doing this! And watch your spelling and grammar too. That makes a difference as well. Don't complain about anything at first. Be positive and lighthearted. One more thing, don't over use emoticons. Direct communication is better.