There is no end to this game. Ideally you would have all your buildings at max level, learn all knowledge and have hero and all shamans at their max levels.
If you have a few $$$ to burn then you can do this quickly. Then you have to get in a clan full of members with similar stats to yours. After that you take on the challenges and aim for top spot in everyone.
Once you have a clan that can easily get top in every event then there is nothing left.
If you don't want to spend any money then get used to getting wiped out with no come back and getting demotivated very quickly.
Checkout this post https://plarium.com/forum/en/vikings-war-of-clans/586_tavern/131435_how-can-players-who-won-t-spend-money-ever-compete-/