You should learn more about women. We are guarded around men we don't know and have every reason to be. It's a strange dance when you get to know a man. Is he nice, respectable, and safe? Women can be a man's partner, yes, but they can also be his victim. We do not have blind trust in men, we can't afford to.
I could meet who I think is the nicest guy in the world, go on a date, and be date rapped. Do you ever worry about that as a man? I could get into a relationship with a man I think is wonderful and stimulating and he could end up abusing me. It's a hit-or-miss game for women, and we use our best judgment but sometimes that isn't enough.
So yes, women are guarded. We are sizing you up from the minute we are interested. It's a shame, but can't be helped. Men can be dangerous to women.
Take it slow, develop friendships, be forthright, and be honest. When a woman trusts you, you will then see a difference. If you appear in a rush, that is a bad signal. It's suspicious and won't get you very far.
I like to think of the two sexes as animals. Dogs, and Cats. When you approach a dog, depending on its size and demeanor you take precautions. It could potentially hurt you. When you approach a cat, it usually takes those cautions with you, because you could hurt it.
Trust is essential. So just concentrate on building trust. This is of course just my take on it as a woman and one who talks to a lot of women about relationships.
A great place to meet up with people is hobby-related clubs, sports clubs, and entertainment clubs. Join some, and become friends with everyone there. Sharing interests will help break down that wall.