Not all of the spells work on here, a lot of them now seem to be 'fantasy', it's called 'fantasy' for a reason.
Some spells do actually work, but don't believe everything you see or hear.
For example, if it is a spell to turn into a werewolf or vampire, witch seems to be very big on this site, those type of spells don't work
You can't change your DNA, eye color, height, things like that.
For another example, you could cast a weight loss spell, it won't do all the work for you, but it can give you some confidence in losing weight
Spells should be the least of your concerns if you are a beginner, studying should be number one with starters.
If you have any more questions or want anything else explained more, feel free to ask.