How To Get More Star Coins
First complete a story campain level. Then after you do if you go back to the same level and there will be star coins.
Different Attack Types
Warriors can do 4 attacks. A rapid stab attack (press x 5 times in rapid succession), a shield smash (rt twice in rapid succession), a dash attack (forward and x at the same time), and a spin attack (rt and x at the same time while enchanted). Mages (While enchanted) can do a super projectile by pressing rt and a at the same time. Clerics can also do the warriors shield bash by pressing rt twice in rapid succession. Use these attacks to do more damage and allow new tactics.
You can level up fast by healing other players who are wounded , or assist them when they are in a fight they can't handle , or just assist them by warding off others when your teammate is constructing. (Those are for multiplayer only).