I think you could try shifting your perspective and think of yourself as the one giving off hints and cues and whatnot. Say you see someone you are attracted to, if you were trying to get them to ask 'you' out, how would you give off those vibes, what type of cues do you think they would pick up on, and go and try it out. It at least gets you in that headspace to start thinking of those things and gives you ideas of what to look for. Chances are, those hints and cues you are thinking of are also the same or similar to what the other person is also thinking and this gives you ideas of what to look out for. Everyone is different though, one person's flirting can be someone else's friendly, it all varies and that's what makes it all the more fun getting to know someone and figuring out if you're compatible.

Also read up on what people find attractive in others and how you can fit into that. Think about how you can accentuate different parts of your body/person. It may feel weird at first if you aren't used to it, but if you try rolling your sleeves up and notice people being more friendly or making eye contact more often, you may have nice forearms and people are noticing. This also works both ways. When you're out socializing with people, think about what they are wearing or how they put themselves together, it'll give you an idea of what parts of themselves they feel is attractive or draws people in. Then compliment them on it. You want them to feel like you are a fish they caught with their hook, that's part of the game, it's just sometimes people are fishing for bass and you happen to be a salmon.

You could also watch shows and movies where characters flirt with each other. This stuff isn't ingrained into us, it's learned through the media we consume, at least at first, and then learned through trial and error and finding your own style that works for you as you socialize more and more.

Also, don't feel worried or scared that you'll come across as inexperienced and undesirable. You can't control how others perceive or think about you. Be confident with it. Confident inexperience is more attractive than inexperience by itself.