Hey there Pyrrhia,
Unfortunately,I don't know any of the "best" ways to create and test a spell, but I do advise you to always put safety first and try not to involve third parties in them.
As far as the avatar, just follow these steps...
Keep in mind that you'll need to have a picture saved and ready before you click on Choose File. Hope this helped!
Rodrig you will have a better time making your own forum rather than hiacking someone elses forum thread.
Long and short, no one can tell you what it is like to be immortal, because it is impossible for anyone to be immortal (physically at least).