Here's some great tips on how to walk in a high-heel wedge. The high-heel wedge is often preferred by women who prefer a thicker heel and a more stable base. Remember that your foot placement should always be the same, where you strike on the heel first, and then rolling through the ball of the foot.
If you're used to wearing the thinner stiletto heel, the wedge is going to feel a little bit different, and you may feel less stable. I recommend walking around the house, getting used to the new shape of the shoe.
If you still feel unstable in the wedge, I recommend doing ankle-strengthening exercises and balance training, so that you feel more stable in the wedge. For a wedge heel that does not have an ankle strap, some women will complain that their foot slides out of the shoe. I recommend gripping the shoe with the front of the toes, as this will increase your stability with each step you take.