When you get more villages you will build defensive villages with only defensive units. Defensive units are spears, swords, archers and heavy cavalry (which can also be used for offense). For your first village it is best to go all offense and the beginning of the game is geared towards offensive players.
The only defensive units I make are the first 50 or so spears I use for farming early on. If someone starts to attack you, it is best to just dodge the attacks and "hide" your resources in the early stages of the game. If your attacker can't benefit from attacking you then you have a better chance of them leaving you alone. Its not until players get a workshop where they can build rams and catapults that they can actually do real damage to you.
EDIT: You will end up building a level 20 (max) wall in all of your villages but if you don't build defense in your first village then there isn't much point to a wall anyway. Unless you're being attacked I wouldn't build your wall past level 5 for now.
EDIT#2:You should probably post any more questions in the questions section :icon_wink: