Are you taking estrogen? Maybe you should search the site for a group for transgendered people. The q&a will probably just tear you apart.
I am a 60 year old man who has recently admitted to himself that he wants to live as a woman for the rest of my life. Lingerie is actually simple. Get an assortment of panties, various colors and styles, silk if you can afford it and definitely lacey. Bras are a bit more trouble, If you are comfortable with the idea, get yourself fitted for a bra properly and buy several, in various styles and colors. I prefer a waist cincher to help mold my body, but a corset also helps to push the loose flesh on your chest up into the cups and form some small, but nice breasts. I usually wear pantyhose because the are easier, but I love to wear a garter belt and stockings. To wear stockings your simply bunch them in your hands, all the way to the toe and work them up your leg.
Go to a Women's clothing store and talk to one of the more mature salespeople; Chances are excellent it's not the 1st time they've been asked and definately know their products and what you would prefer.