just some basic tips for beginners: firstly, if u have progress a little bit into the game and u army dies, ur pretty much screwed, better of restarting the whole game. archers are really good, (especially get those ones with more shots , they have lesser damage then other ranged with lesser shots, but they are better in a long run). Peasants are OP!!, they are really good meatshields for ur archers especially with teleport or speed up. the best skill u can probably get from leveling up are probably attack and defense.. trust me, they will help ur team alot.
for ghosts.. never never send meatshields, e.g( pixies,peasants, even boars) against them, try to teleport them away or slow them down so that ur ranged units can kill them before they grow stronger.