I have been playing for a few weeks and have several offers of advice. My first overall advice is that this is a game of patience. Time is your ally.
1. Get to 25 allies as soon as possible. Get allies by invading other people (you don't actually attack at this point) and select rival profile and look into the comments part for people spamming their ids. You can also see the strength of your rival at this point and the gold they to see if they are worth attacking. Once you have allies you can visit them daily for 25 free gold x 25 allies is 625 free gold every day (max free gold this each day).
2. It is pretty safe to level to level 15 pretty quickly...beyond this you should wait to make sure you have all money buildings for each level before moving forward. You should always be constantly upgrading, building, expanding your vault and expanding your kingdom.
3. Focus on defense early. The siege workshop is your best avenue early on. The ballista offers 9 defense at level 3. And then the blimp at level 7 offers a whopping 17. I found the other buildings only useful for quests. Get simple units early as that is all you can afford, but after that focus on quality.
4. You get three units for your army for every ally you have. Make sure you have enough weapons and armor for them. Cheap is key early. Money is better spent on units as that provides the best attack/defense for gold value. I always get the tavern twins for 8 gold and the footmans leather for armor at 32 gold each. Just having them makes a huge difference in attack/defense.
5. Always vault all your gold. People won't bother attacking you if they don't get anything out of it. I have only been raided a few times and even if they are much stronger than you, they will only attack once and then search for better rewards elsewhere. Conversely if you are raiding someone and they don't yield much, move on. Always check your opponents attack defense before raiding them.
6. Upgrading money buildings is tricky. If you are someone that can check the game frequently, you are better upgrading farms and cottages as they provide the most cash quickly and frequently. Whereas as if you only want to check a few times a day then you want to upgrade silos. You also have to weigh the benefits of cost and time. Higher level upgrades take longer and are more expensive than lower level upgrades.
7. You should also monitor your allies. You can have 5 allies for every level. If you have good defensive units that are equipped, you can have as many allies as you want, but this also put you in more elite company on raids. I choose to have my allies near the max.
8. If you find yourself getting destroyed, remove some allies, don't level and focus on upgrading buildings and units. If a few days your picture will improve greatly and it's much better than restarting. This process is known as turtling.
9. Unless you are independently wealthy, don't waste money on the jewels. You can get some cool units but at what price. The game also makes it real easy to accidentally waste large numbers of gems on reducing upgrade times. If you do spend gems, get the units you want immediately and don't stockpile the gems. Conversely, never raid or invade a gem player. If you go to their kingdom, look for gem buildings. If they have them, move on.
10. This should get most people going early on good luck and feel free to look me up 644-935-173 I will accept all allies if I have room.