I’m glad you have your wife’s enthusiastic support. We can offer some insights, but in the end, she is your most reliable source of guidance.
Don’t worry about feeling unsure. That’s perfectly normal. Hesitancy is equally normal when you are facing big potential changes. So my advice is to just take small, comfortable steps from wherever you are in your life. It may begin as simple as incorporating some feminine items in your otherwise drab appearanc You may start dressing in a more feminine manner at home. Or maybe your first time out in public. (Dinner with your wife sounds nice ;). Whatever works for you.
Take your time and enjoy the freedom and support your wife is giving you. Not all of us are so fortunate!