i don't think girls are attracted to "innocent" side. I tend to be quiet but I am definitely not innocent by any means. I think you're trying to convince yourself/justify that girls will tolerate your lack of experience and shyness (both very non-confident things, which is the opposite of what girls like).
i know a guy who is physically a good looking guy I guess, in fact he put up pictures on a dating site and told me he got a lot of messages. I believe it because all you can judge in a picture are looks (an "about me" paragraph can't really capture your character and who you really are as a person), so just based on looks I'm sure he got girls' attention. the thing though is that he is really such a dork in real life lol. I am not even trying to be mean, I like him but really he is just pretty awkward, too "nice guy"-ish, has no social grace I guess, especially with women. this is exactly what gives him problems and what turns girls off (it's true that girls care more about character/personality than looks alone).
so to go back to your question, if you think you're in this kind of situation, just be more talkative and less "innocent" (what exactly do you mean by "innocent" though? I assume you're basically saying you are not as much of a rebel or risk-takers as some other guys. be smart but don't be a pussy). be yourself but fine-tune yourself to be more desirable to women by being more confident, brave, aware of proper social etiquette, etc. this will far outweigh being just good looking and in shape.