Try whatever your comfortable with, if you in a big city and you know there won't really be any reprecussions to a random approach and getting shot down, then go for it. You are likely to have a very low success rate considering you said you look 14, and you talking about 25-30 year olds. But if you are never gonna see those women again, then whats the worst that could happen.
But If you a teenager(guessing 16-17 or so) then I would say shoot for 15-22 y/o girls. You might have a shot with a couple in the 20-22 y/o range, but it will be hard to match their maturity level. Most girls date older guys as it is, so I would find it really hard to believe you could 16-17 and have much success with a 25-30.
But I have been proven wrong before, but if you are really 16-17, and approaching obviously older women, you best bet is to at least lie and say 18-19. If they ask to see your ID, then just play it off with C/F, like say "Wow your afraid you gonna take advantage of me already and I just met you."(in laughing, sly smile kind of way.)