Since you're not experienced in walking in heels (at least... I think you're not..?)
you should avoid tall heels and spike heels (something like
this)
If you can find a pair in your size, try to find heels that have a short/fat heel (like
this)
That last example was more of a clog than a heel, but you get the idea.
Oh and they should be a closed heel, something that has a back to it.
If it's open like in that last example, you'll end up sliding out of them a LOT.
Having an open toe (like
this) doesn't really matter in terms of walking.
They just show off your toe cleavage (yes that's an actual term...)
The key to walking in heels is to not think about it too hard.
The more you think, the more likely you are to fall flat on your face! XD
Since the weight from the heel of your foot will be on a much smaller surface,
you should place more of your weight at the toe.
And dainty steps! You can't successfully walk in heels if you stomp around like a neanderthal! XD