Well we need a lot more information to be able to help you. What spells have you tried? Have you studies about spells, energy, meditation, circle casting and other subjects refered to as 'the basics'? Did you focus? Did you put forth any effort to achieve your goal? Did you dwell on the spell once cast? These are some questions you should answer or will be asked by people to try and determine where the spell went wrong.
Magick is a natural force, so any spell going against nature does not work like transformation, teleportation, levitation, flight, invisibility, having wings, animal features, or the majority of spells found in the Fantasy and Trick sections will not work because this is not how real spiritual magick works. These spells were primarily posted by Spell Caster Coven members who just discovered people do cast spells, but did not go past a Harry Potter book in terms of study and believe magick is like in Hogwarts when it has more in common with prayer.
Do you know how to work with energy, meditate, cast a circle, and focus/visualize? If there is no energy, if your mind is thinking about other things, or you are merely reading off a piece of paper, and not connecting with anything, the spell will not work regardless of how accurate and real it is. You need to put all your mind, body, and spirit into your spellwork, if you're physically inside the circle casting a spell, but mentally are thinking about what to make for dinner, or perhaps calling your friend after this spell, then it won't work. Belief is another key component, if you don't believe in magick, a particular deity, or a spell working, then it most certainly will flop.
Say you cast a working love spell correctly, but you just sit at opposite corners in the classeroom from the person you cast over. The spell will fail. Spells don't turn people into zombies who instantly walk up to you, proclaim their love, and ask you out. A spell will effect the energy surrounding the person placing the two of you in a situation where you could ask them out, or at least get to know them. Certain spells are meant to overpower a persons free will, but even in the case of such a spell, you need to talk to them, the spell puts them in a position where they give you a chance. Spells that force your will over them do wear off, when is different for each person, so you need to recast often, but again, you need to make an effort.
Lastly, dwelling on a spell will break a spell. You need to cast and move on. Say you cast a money spell, and are convinced you will find money on the street because you did this spell. The spell might not work this way, it will influence your boss into giving you a few extra shifts, but you're so convinced the money will be found, you turn down the extra work. After a month, you get mad and claim the spell didn't work. You need to keep an open mind and not walk around convinced something will happen a certain way.
