How do I earn more silver? As I see from the shops, it costs at least 20-30k for the buildings and I only have 6k v_v. How do I start? 

Well, to start with, don't buy the blueprints from the statestore: they're way overpriced and you can geet them much more cheaply from the Item trades or via a wanted ad.

The ways to earn mony are many, but the most simple are questing and exploring. I've pretty much bought every quester beast I could find over the past two years, and I highly recommend you doing the same. There's a list of common quests in the Player guides section of the forum to start you off. You can even find Striped black dragons and Pure black pumas in the pound. Look for blue and white symurghs too.

Apart from questing, use exploring to gather silver. Level up your pets as much as possible, because the higher the level your pet has, the more silver it finds. The cheapest way of doing this is find good pets then put them on the arena in autobattle mode. Each win gives you XP so a good pet will level up quickly without taking any money, unlike training via a ridinghall.

That was a good answer from arete. Often with lots of refreshing you can find high-level pets in the pound, including occasional level 50s. They get the biggest, richest islands to explore.

Only thing I would add: selling vermillion is how I got most of my silver at first. It's worth 500-900 silver each, so 10 vermillion can easily go for 5000, 100 vermillion for 60k+. If you're not using it for breeding, collect it from islands (and build a golem to multiply it) and sell it.

Thanks!