what have you learned so far? spells need energy and focus among other things to work. if you just light a candle and read a few words the spell won't work. you need to meditate, clear your mind of everything except the spell, charge each item with energy, and visualize your desired outcome. one final thing, after casting the spell, normally you need to put forth the effort to achieve the goal. a job spell will fail if you don't apply for a few places.
study 'the basics' like meditation, charging/grounding energy, circle casting, stuff like that if you want your spells to work. if you're casting a spell to, say, fly, this won't work, so be sure you know the difference between working and non-working spells.