Helen, Men are more likely to talk to a woman who acts open and friendly. It's difficult for a guy to break into a group of women who are chatting among themselves and ignoring everyone else. One of the most common complaints I get from men is that women act disinterested and unapproachable.
When you go out, smile, nod and say hi to as many guys as possible. The others will see that you're open and friendly, and they will be more likely to get into a conversation with you. It's OK to introduce yourself, have a short chat, and exit with a friendly compliment such as "It's been fun talking with you."
Be sure to stick to light topics. The point is to make contact, then to get to know him better later. Most people become comfortable after several brief visits, rather than if they engage one long discussion.
If you engage in a long or intense discourse about personal subjects with someone you just met, you may give him the impression that you're desperate. Save your relationship questions for much later. Just see if you enjoy his company when you first meet him.