I have to take care about this pool but I am not sure

For Filter, there is 4 valves, which ones I have to open and which have to be closed ?
One is Shallow Skimmer and Deep Skimmer, there is one for Hower and one on the bottom I have no Idea where it could go... will be bigger size when they are clicked





1) How do I have to set them for filtering ?
2) And how do I clean the filter afterwards, that it dont floods everything ?
3) And bigest question for me is how to set it for backwash and how long to wait until its ok to start, hope somebody can help..
And how many litres is this ? At the beginning maybe 1.5cm deep and at the end 2.30cm, PH is complete red I have PH Minus and Chlorine is almost nothing I can throw some in and measure it with the tool..
Hope somebody can help me im clueless
