By default, visuals with vertical and horizontal axes have labels on these axes.
To remove the labels on visuals that use X Axis and Y Axis, navigate to the Axes menu, and de-select: Include x axis label, or Include y axis label, or both.
To remove the labels on visuals that use Dimensions and Measures, navigate to the Axes menu, and de-select: Include dimension axis label, or Include measure axis label, or both.