I go for the freeze, the motion blur can work in different scenarios, but it's not something I shoot for.
shutter speed should be at least 2x focal length, I shoot wide open at 2.8 for the most part and an appropriate ISO to achieve the mentioned shutter speed.
with sports you want to frame the shot where the ball is in every shot, helps tell the viewer what's going on. My exception is when shooting the linemen in American football, which is what my son plays so I have to get some action shots of the linemen.
it will be trial and error and the main thing is watch your backgrounds, in focus backgrounds take away from the story.
For my night time high ISO shots I will bring the shutter down to a minimum of 400. During the day it's 1k plus depending on the sunlight. I really prefer to shoot at 2.8 for light gathering and background compression, which is referred to blowing out the background.
so without knowing what is in your equipment bag, it's hard to provide exactly what you should do.
i also shoot full manual with RAW format, it gives me more to tweak the shots if I need to. So I shoot auto white balance and adjust it in Lightroom.
i can go on and on, so ask away or post up some examples and we can tell you more about what to do.
if you want to see some of my examples then feel free to take a peek at my website in my signature. All of the football pictures are open to the public, but the baseball is locked down for privacy reasons.