Hide/show Gmail Labels
If you use a lot of labels in Gmail, the list in the left column can get quite long. There is a simple way to show only your most frequently used ones: underneath your list of labels on the left, click on “More”. You can click and drag any label from above the line to below it, or vice versa.
Another way to manage your labels is to go to Settings (the gear label in the upper right corner) and then click on Labels. From here you can click Show/Hide to choose which labels will be visible in your list.