First off, I'd like to say welcome to the site and that I hope you find everything you are looking for while here. ^_^
Then, I'd like to promptly say, "Work on your basics before you try spells." The basics are meditation, visualization, energy flow and control, grounding/centering, shielding/circle casting, and correspondences. You can find information on all of these within the General Info forum.
Now, about the candles, it can matter whether you use scented ones or not because generally people use certain candle colors and certain types of incense for certain intents, and therefore when you use scented candles you should ensure that the scent goes along with your intent in some fashion.
Not everyone has to or does worry about the colors or whether they are scented or not because they can use the candle regardless of either to cause the intent they wish. I personally use scented candles from time to time, but most of the time I use white unscented tealights. They are small, easy to use, and cheap. You can find them in any craft store or Walmart (and probably several grocery stores) for something like $1-4 depending on how many tealights come in the bag/box. ;)