Attacking other players is a simple process, the game has a built-in battle calculator. One, you can't still be in protection mode. Then, step one, find a suitable target (In the beginning this likely means inactives, later it'll mean fat and or open targets, or just people you feel like hitting). You find a target by going to the Coven link and looking through covens. Then, click the target's name, this will open the analysis page. Click the Spy button, it'll either give you a SoM or it won't, if it doesn't spy again. The SoM has a link, Feed to Battle Calculator, you click the link, this opens the battle calc. You check the boxes next to which characters you want to send, enter in military units (you must send at least 10 military units). Click Test. It'll either tell you it'll work and give you a link to click to send the attack or it'll give you a red failure warning.

My advice is two-fold, one, be careful how much you send out, my players are the most loveable but vicious on the net and if you send out too much they'll hit you. If you don't know what safe defense is, message your coven leader, message your clan leader, or message me in the public forums (click public forums, member list, I'm right there at the top, Juxta).

My second piece of advice, if you hit somebody leave them alone for a while, give them 4-5 days to recover, hit somebody else, it's a small game, and repeat hitting the same targets will get you removed from the game.