RE: what do i need to do
A laser isn't necessary and they should only be used by those that are experienced enough to understand the possitives and negatives of them.
You can usually eyeball the centershot.If you nock an arrow and look down at the bow from the top(above),you should see the arrow running pretty close to center of the stabilizer to just outside of it.If it it is way inside or outside of it,then adjust it untill they are fairly close.
Then you are ready to do some tuning.