Play games
Choose the game that interests you and play itfor free.
Complete the quests
Every game has some quests for which you will receive Soul Gems.
Receive rewards
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
For the first reward, you need to play and finish 3 games (you don't have to win them) With your starting tanks you are given play your first game, you can either play the game normally (trying to kill enemies and play the objective) or you can get straight into the action and die as fast as possible. When you die, press escape and click on return to barracks.
When you are back in the garage area, it will say the tank you have previously played on is in battle. This means you can't use this tank until the end of the game (this doesn't apply if you finished the game whilst playing it)
This is when the other tanks you are given comes in handy, use these tanks to play more games and repeat. When you finish 3 games, log out of your account and redeem your prize of 300 soul gems.
Carry on doing this until you reach the 10 games played aswell.
As for the 100 wins which is the 3rd prize, I suggest playing the game in your spare time until you reach it. Enjoy the games you play and dont rush! it's a fun game afterall.
Best way to kill an enemy tank
The best way to kill an enemy tank is to fire at the side of the tank (or at the tracks to stop their movement)
The sides are the best place to hit the tank because there is alot less armour on the sides.
And the tracks are the second best option because when done correctly they are completely immobilized.