Ok you have two choices in my opinion, O'tangs and Abec11's.
Otang's
you will want the stimulus, durian, or fat free. The stim and durian are the same wheel except the durian is slightly larger and the fat free is slightly skinnier and smaller. they are all good wheels. Get 86a to 83a's. They slide easily but can be slightly chattery (kind of vibratey) but last a long time and are fairly hard to flat spot (when you slide on one part of the wheel for a long period of time and cause it to become flat)
Abec11's
you will want the 70's flashback, freerides, or any of the other classic thane wheels. you will want 81a to 84a wheels as these slide really smoothly. They are slightly more prone to flatspotting than the Otangs but they are rarely ever chattery. These are also cheaper, but may last not qutie as long as you will getting a softer wheel. Don't let the lower duro on these fool you, they are my favorite sliding wheels and are amazing. Since you are just starting you probably wont have to worry about flatspots also.
Over all i would get the Abec11's. They slide smoother generally (to most people) and are cheaper. You will probably have to order them though as they seem to be hard to find, but you can always find Otangs. Needless to say, good luck
**Also, you should try a pushup slide as your first slide in my opinion, and then try colemans, Just look them up on youtube to learn how to do them
***Pushup slides seem scary but are incredibly fun and are super stable, if you fall off your board by some crazy weird chance, you just slide on your hands and toes of your shoes
****** GET GLOVES AND KNEE PADS AND ELBOW PADS AND ESPICALLY A HELMET!!!! you will probably only skin your arms or knees without them, but it is nice to have them on and be safe.