Ah, the Look squeak!
I rode Look pedals for years, and still have them on my kid's bikes. Strong and durable, but the plastic of the cleat rubbing on the pedal gives you the squeak. Do a search on this forum and you will see lots of remedies. I used parafin wax, which you can buy for a couple of dollars at the grocery. Rubbed it liberally on the pedal surface and the cleat about every other ride. Did the trick. I would avoid oil based lubes, as they will attract dirt and just make a mess.
Regarding "arc", Look pedals have two adjustments. The knob on the back is the ARC adjustment, which controls the "float" of the pedal, or said differently it controls how much you can move your heel from side to side. Set it at zero and your foot is locked in to a single position. 9 degrees is the maximum, so it allows your heel to move 9 degrees in and 9 degrees out (before unclipping). I found I always left it at 9 degrees, as unless you have your cleat position dead on you could strain knees, ankles, etc.
The other adjustment is release tension. This is the allen screw on the pedal surface. This controls the tension for the clamp in the rear. Loosen it, and it will be easier to clip and unclip. If you are new to clipless I suggest you do that. Makes it less likely you can't get out on that time you forget to unclip at a light. Tighten it, and it makes it harder to get in and out. I always rode mine all the way tight, but I am a larger rider so getting in was not a problem. My wife is smaller, so get them too tight and she could not clip in. I just liked the feeling of being in the pedal and not worrying about it releasing when mashing out of the saddle.
So:
1. make sure you get your cleats in the right position on your shoes. Put them on and do some spinning on a trainer. Move them around a little until they feel comfortable and in the right position.
2. Adjust the float (arc) and release tension to your liking.
3. Buy some wax, parafin, etc. to lube the pedals.
4. Enjoy
Happy riding.
