Scripture says that God will give us more than we can ask or think. This is because we don't really know what we want. We ask for a million dollars, when we actually want financial liberty. God knows it takes more than a million dollars, so he gives us more than we can ask or think.
That's why we must ask with openness. To have, say, "a million dollars or something better." God knows it takes more than a million dollars, and he'll try to give it. But if we're hung up on "one million dollars," we won't be able to receive the "more than we can ask or think."
So, ask. Ask away. Realising that we don't fully know what we're asking for. So ask for "X or something better." And be willing and ready to be surprised.
Meanwhile, as you mature as a person, your asking will get wiser and more accurate to begin with.