To expand your village you need resources. There are several ways to earn Gold and Beer (and Nectar in later stage of the game). The basic one is by building factories and containers. Remember to upgrade factories to improve their efficiency. Upgrade containers to improve their storage capabilities. This allows you to store more Gold and Beer and expand your village with new buildings.

If you reach the point that you don't have new buildings unlocked, upgrade your Townhall - the most important building in your village. Keep it in the center of your village and defend it well! There are several types of constructions you can build: Production (factories, containers and Builder's Houses), Defensive (towers, traps and Walls), Offensive (Taverns, Forges, Boats and heroes related). The best way is to keep balance between all the types, and one of the ways to achieve it is to follow tasks from the Missions window. You can also earn resources by attacking other players' villages and looting them. Remember that you can't loot (nor lose) all resources present in the village in a single battle.

Also, if you connect your game to Facebook, you will be able to donate and receive resources gifts between friends. And finally, you can get resources from many different bonuses that are spread all over the game.

— Game's Help Pages