You can train Runecrafting fairly fast at the RuneSpan. The entrance is at the Wizard Tower; the fastest way to get there is using the wicked hood's "teleport" option.
The Runespan doesn't give you any money; nor does it cost money. Once you have a certain runecrafting level, you may want to make runes instead. This is slower than the Runespan activity, but you can earn money while you train.
It's just to the west of varrock.
about 70-100 days when you have got the level for nature runes
It's hard to tell exactly how much you will make from Runecrafting, all we can say is you should make a lot depending on what runes you make.
earth or fire cause they are very close to banks
you can get an easy one at Draynor Runecrafting Guild for a small price.
Achieve level 50 runecrafting.
Not that I'm aware of, besides a wizard runecrafting hat from the runecrafting minigame and a hood that goes with the runecrafting skill cape.
Kill Gremlens
The Runecrafting Guild is part of the Wizards Tower base in Draynor Village, you will need level 50 Runecrafting to access the portal on the 2nd Floor.
Make runes. Air, Water,...
Nope, f2p can get certain runecrafting staves too. You just need to get a tailsman staff, a air tailsman and most importantly, at least 50 Runecrafting to get the air runecrafting staff.
It's just to the west of varrock.
go to runecrafting guild and gain points then buy.
At the Fist of Guthix. The runecrafting gloves cost 75 fist of guthix tokens each. You can buy Air, water, or earth runecrafting gloves there. Each set of gloves have 100 charges.
You use rune essence/pure essence on a altar. (runecrafting)
You go to the Runecrafting Guild and you play great orb project.
The Great Orb Project is a RuneScape minigame. It is only for people who have access to the RuneCrafting Guild. It grants you RuneCrafting related rewards.