It is a "Simple script" but......
The lvl 3 would not be able to teleport to lumbridge due to magic level being too low, other than once every 30 mins, it needs to walk there.
But I can certainly make it for you if no one has yer.
A few questions for you -
Would the lvl 3 be mining the essence or buying it from GE?
if buying from ge:
how would it get the cash for this? (can trade another player for coins or make the money)
if Mining -
Character has to do Rune mysteries quest before being able to mine essence
Would the account be a Fresh account (no tutorial island completed) ?
do you want the character to automatically complete everything from the start?
(Random name, appearance and complete tutorial island, then go to next task)
Do you want the character to train Magic to gain the level necessary to teleport to lumbridge?
if Yes - Has to gain the supplies for the skill first
How would you like to train for this method?
if NO -
Character will walk to lumbridge
How often do you want this character to walk? (after it gains 1k essence?, Per Inventory?)
DM me if you need this still.