That is your quick settings menu, and the icons are quick setting tiles.
There are two stages, one appears with a small touch or swipe, that brings down the first few. Consider these to be your 'favorites', the ones that you use the most.
The second stage, which appears with a full downswipe, is all the rest of the quick settings. There can even be more than one page of them.
First, bring down only the first stage, the favorites, and count how many are there. Keep this number in mind, so that you put this amount of the most used first when you edit.
To adjust what settings are there, pull down the whole thing, the second stage, and look for a small pencil icon. That is for editing.
You can now long press and move them to rearrange the quick setting tiles.
To eliminate a tile, long press it and move it to the very bottom.
There should be a line that is labeled to the effect of 'Drag tiles down to remove'.
Also, if you see tiles below that line that you would like to add, long press them and bring them above the line.
You may need to play with it a few times to get everything just right.
Be sure to pick the appropriate number of favorites, and put those at the very top.
That way they will be the most accessible.
