My first 'single' player game as Gothones, I totally ignored objectives, I just built CDR the hard way. I came in second in the finish. Was in first with 15 turns left, but Parthia overtook me, they were generating a ton of cash and that earned them a higher Legacy rating than I. But it was a good game for me, and a good learning game.
I am in my first Gothone Civil war in my current game with MD, I think I'll be okay, but we'll see. Again, if you can reach 'tier II' quick enough, there is no Civil War.
I think those countries to the West of me are a lot harder, because all your neighbors are attacking quickly. Cherusci, Marconi, Rhaeti. In our Alpine War game, it's not an issue, because your neighbors are human allies.
Averni is a good beginner region, because your starting Army is very strong!.. Belgae is a Chiefdom, I have had successful Single and MP rounds with them.
British Isles can be successful beginning. But if you're on Great Britain, that can be tricky start because of close proximity to potential Enemies., So Ally with them and chose the right time to go to War. Hibernia is weak at start, but does have water around it to give a lil isolation.
Important note in the very beginning, don't attack rebel plains if you don't have a lot of units for 'frontage'. Also create a couple warrior units before you start your first attack, as sometimes when it says possibly 3 units, it's actually 5! That's where Averni is great for the beginning, cause your initial Army is strong enough to attack immediately.