If you're new to EB don't start as any of the following factions:

Casse
Hayasdan*
Pahlava*
Pontos
Saka Rauka*
Sauromatae*

Even i struggle with the ones with a * at the end and i've been playing EB for about 2 years now. I can eventually become a superpower with all of them except Hayasdan who i just can't seem to get my head around.

I'd try something a bit easier for your start. Aediu/Averni are barbarians but have it a lot easier than your choice. Getai have it quite hard because their troops are all light and their neighbours are all heavy, but it's still quite easy compared to Sauromatae. Hell i think even the Saka Rauka are easier than Sauromatae, provided you take your starting army and raid/exterminate cities with landmarks to the south. The Seleukids have one city just beneath where the Hayasdan start with a nice population and a wonder to destroy which'l give you 15,000 denari.