I strongly agree with jmcallister, its best to start with the "basics" before you attempt any spells. In my opinion, belief that magic works is a major tool in successful magical workings and if you jump in and try to do spells without having a good idea of how and why magic and the energies unseen work, your success is very limited... so basically if you start doing spells and they don't work your belief in magic is diminished and it could set you back from where you could be if you had studied first.
With that said, if you are willing to take the risk I would start with a spell that you would be able to recognize that it worked and would be less likely be able to be put off as a mere coincidence. I suggest a money spell or something physical to be brought to you, that way when it shows up your faith in magic will go up and you will want to learn more so you can achieve more. I wouldn't try to go "Too big" or get too detailed... just ask for something simple and keep your mind open to accept what it gives you in whatever form it may be.
There are many beliefs and what we call "paths" out there because there are many different types of people. Some may suggest that you should ask for things that are unselfish or the universe will think your selfish and not help you. I say that it depends on the type of person you are because I have seen many people that I consider to be mean and unworthy of being helped because they don't care about others, always having things "go their way" and seem to have great luck while those I consider to be of very good character and good people struggle thru life so I feel my advice above would be a good start.