Step 2: A Little Bit Further
Step 2a: Trading For Profit:
Once you've completed the quests start building a marketplace, personally I go for level 3 but by the end of this stage you might want to be level 5 or 6. Offer wood or clay for sale in exchange at a roughly 1.5:1 or 2:1 ratio (in your favor) in exchange for iron or crop. To make this easier to get to you can change your hero to producing just wood or clay, but remember to change back when you start going negative. You can use Gold to NPC the extra crop and iron you are getting in.
Step 2b: Warehouse & Granary:
Upgrade this as you are increasing your marketplace, most likely you will be getting in quite a lot of crop in while getting less iron so I'd suggest building in a way more biased toward the granary. You shouldn't need to build it very high as you will be NPCing when needed.
Step 2c: Cranny Up:
This is an aggressive guide but I have to suggest crannying up, my guide hinges on being able to raid while offering absolutely nothing for raiders except casualties and a waste of their time. Since you will be NPCing the maximum number of crannies you should need is 1 and I'd stop at about level 4, but later on if you do come under attack then feel free to increase it.
Step 2d: The Wall Shall Rise:
The wall is an important tool in Travian 4 at the early game, it allows players (Romans especially) to cause casualties on attackers without leaving a single one of your own troops in harms way. As soon as possible build your wall to level 4 (before end of BP) as this will ensure that 1 clubswinger/maceman is killed when a Teuton attacks you, this may not seem like much but if every time the Teuton attacks they lose one of their troops and gain no resources then you most likely will not be attacked in the first week again.