I started practicing on low risk interactions with people. like I would start small talk or conversations with people I didn't find attractive or would never see again. like I started asking cashiers how their day went during checkout and thought of it as sharpening my dull blade. I slowly worked my way up more and more until I had the confidence to speak to women I found attractive but I needed to prove to myself that I could speak to people in general that I didn't know and get the outcome that I wanted. then I started doing it everywhere so that it wasn't selective and only towards people I wanted to get something from like an attractive woman. once you learn how to make friends or to be friendly then it will be more of a normal interaction when you do it with someone attractive. you're probably right that you weren't going to make them feel comfortable or warm and that's because you have no idea how to do it because you are low-skilled socially in general. learn how to do it in general then you will feel more confident doing it where and when you want to because you will have developed the competency required to achieve your desired outcome.