Nerves are setting in! Advice please!

My best friend happened to set me up with one of her guy friends. Him and I were on the phone for two hours. He's so down to earth, have things in common, he's genuine so that does help a lot that we connect extremely well.
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But.. my ex still talks to me. He has been extremely on and off with me which is why my friend introduced me to her friend in the first place. I don't want to hurt my ex and make him go through more confusion or ruin a potential relationship. And before anyone comments my ex is an ex because we had a long distance relationship which put a strain on us. So maybe finding someone new is my best option? I see my date tomorrow so if you have any advice please give me some. I never had my first kiss either which is something he wants to do if I'm okay with it.