Go to your local recycling facility if you have such a place nearby, and see if they give out composted soil.
- A 15 liter pot of that, should be able to carry an auto fro seedling to harvest, without the need to add fertilizer.
It's a very good way to get experience as a first time grower, before you start spending money on soil and nutrients while lacking knowledge. And wile your plant grows, you'll have a lot of time to google and read about growing cannabis to prepare for your next grow. ^_^