need to get pump to pull from bottom

[bkny1055]

I have several questions ?? Newbie here <--
1.There is a red Valve that i dont know where to set it to
straight up it pulls from the skimmer
to the right it also pulls from the skimmer
2.which way pulls from the bottom of the pool
3.which way should i use the valves for best results
4.What do they mean by " backwash "
5.Where do i buy the the kit everyone here is always talking about
here are pics

(((((((((WHICH WAY VALVE NEEDS TO BE SO IT GOES THROUGH FILTER)))))))))








Best Board Ever thanks guys for the Help.