The SUEHIRO #1000/#6000 is a great whetstone to start your sharpening journey on a budget. The 1k side on this stone is coarse enough to bring a dull knife back to life and the 6k side is perfect to polish and refine that edge to something that will give you a silky smooth cutting feel and a longer edge life.
All of the whetstones sold at the shop are Waterstones, do not put oil on any of them, you will ruin your stone. Holding the knife at a consistent angle while sharpening is one of, if not, the most important thing to consider when sharpening; thus, maintaining a flat stone is of equal importance. Pick up a truing stone to maintain a flat stone in order to achieve the best results.
If your stones are super worn out and completely concave using a truing stone will take hours to flatten them. Consider purchasing a King flattening stone to get the job done quicker.