Parts is parts
These are perennial body parts questions, and I feel I would be somewhat remiss if I didn't re-answer them every few years. Here are some that have been hanging around waiting for me.
I once tried for half an hour putting my index finger about two inches inside my girlfriend's vagina, pressing with a "come hither motion" and simultaneously pressing the mound from outside. Unfortunately my partner did not experience any extra pleasure. Maybe I have to try again and again?
Yes, yes, very funny. I'm not entirely sure what she was experiencing, but from your phrasing, which could have been cut and pasted from any one of a thousand how-to Web sites, I think you may have been proceeding a bit by rote there. Rather than printing out some stranger's directions, how about following hers?
There are plenty of women who don't have much of the spongy erectile tissue surrounding the urethra and the front of the vagina that we've come, for convenience's sake, to call the G-spot. These women can lie there all day receiving simultaneous come-hither motions and external pressure and only manage to get kind of annoyed with you. If your girlfriend is one of them, I would not suggest "trying again and again" unless you want her to lean forward and swat the top of your head with the TV remote.
You can probably determine whether she is G-spot enabled by letting her guide you. Since the G-spot is, inconveniently, not actually a "hot button," but a collection of tissues sensitive to the touch under certain but not all circumstances, I cannot tell you exactly how to operate it. I'd start once she's already well turned-on, though, and without impatience or, indeed, goal-orientation. Just kind of slip in there when things are already going well and keep your eyes on her face while you try a little deeper or a little closer in, a little harder and a little softer, a little ... oh, you get the picture.
My penis is curved a little. Is that normal, and if not what can I do to straighten it?
Nothing! Do not do anything! Some curvatures are caused by a previous injury that heals but puts a hitch in the sheath of sausage-casing-like material that encases the spongy, sausage-like corpora cavernosa, the working parts of your penis. I don't think that's what happened to you, but if you want to find out how a devastating penis fracture heals, try unbending it.
Yours probably was just made that way. If we were all made in God's image, some of God's avatars would have a dick just like yours. Worry not, and if you have a chance check out some G-spot toys, if the curve looks familiar, boy are you in luck.
I am just a big chicken! How come I am afraid of sticking my finger inside of me? It just terrifies me for some reason, and I refuse to stick anything inside of me 'cause I am just so afraid!!
I'm going to assume you are a teenager, in which case it's pretty normal. Not only do we hear a ton about how it might hurt and bleed (and, indeed, it might), this is the inside of your body. That is, emotionally speaking, some heavy stuff. We spend our very early childhood learning the limits of our bodies where we stop and other people begin, what goes in and what comes out. It is no small trick to relearn boundaries later and start letting new things in new places.
Take it easy, take it slow, and maybe try with something smaller, like a Q-Tip and see how that goes. Also, take a mirror and see where it's going.