go to aubury in varrock, he is located behind the small bank in varrock east of the centre if your looking directly at the castle.
or travel down to the large bank and buy one from the grand exchange or 'G.E', if youve never used this then talk to one of the two tutors at the main entrance.
The wind altar to craft air runes is just south-west of faladors southern gates. You'll find it if you walk southwest from there.
Mostly Fire runes but Law runes and Air runes are not far behind them.
You can find Nature runes by killing monsters, buying from other players, buying from the Grand Exchange, or making them yourself.
There is no staff like this.
runescape
The answer is yes. You do need to supply your own runes.
You can make the at the water altar, buy them from a rune shop, or buy them from the Grand Exchange.
They could be anywhere throughout RuneScape.
To get runes, you can either buy them from the various magic shops around Runescape, on the Grand Exchange, or make them from rune essence and pure essence at the runecrafting altars hidden around runescape. If you need help, my runescape username is Xeyran.
Crafting Water Runes.
No.
crafting runes at alters. Use runes ess at certain alter to craft those runes. Eg water alter you crft water runes.