Newbies are always disadvantageous when they play any kind of online games. Especially battle/survival games are difficult to play and prevail against other players. For that reason, it is always better to take some time for learning how to play the game as well as some hints and tips to gain advantage against others.
How to play Evowars.io ? Game controls and tips
As for the evowars.io unblocked at the school , it is not that difficult to play. In order to move your player across the game arena, you just move your mouse. The left mouse button lets you attack and hit your enemies while the right mouse button enables you to sprint in cases you think you can not reach your enemy.
In order to survive for longer times, you need to prioritize strengthening your player. Your player will get stronger as you level up. Every level up gives you more powers and resistance. Try killing smaller and weaker enemies first.