Nothing ever happens...:(

I agree with Lark as it's nothing to do with the spell being advanced or easy. Magick is magick and spells are just the way they are. What do you consider as an advanced magick? Something that has more steps to do? Or dangerous? I think all the spells have the danger of backfiring and that's what makes spells complicated but not just a specific group of spells. All of them.

Think of this. (again a cooking example. My mind's stuck there today) when someone is going to cook something, they need to know how to cook first in order to prevent any troubles. If someone doesn't know the basics of working in the kitchen, they might just cut their fingers or burn the whole house. But when one learns the basics, he/she can easily cook anything. Cooking is cooking. When you have the recipe, you can cook anything just some can take longer time and steps. Same as magick. Some spells can take more concentration and more steps to have it done.

As it's been already mentioned, first you need to study magick and understand how it works, then jump into casting the spells. I assume when your primary spells failed, your faith went down as belief can affect the spells pretty much as well.