I have a drill press and I want to do an hole at the center of a cylinder but I don't know how to do...Can anyone help me?
I'd create a channel out of wood blocks for the cylinder to lie in and pad it with a cloth. Something like this:
Then I'd use an awl or nail set to create a divot in the surface of the acrylic. This will help prevent bit crawl, though a drill press usually takes care of that for you if you secure the work piece well.
Acrylic melts easily, so either drill fairly quickly or use a fluid bath for cooling.
If you are centering on the circular face as noted in the post, you'd want to have a center finder tool, either one you've constructed yourself or a purchased model.
A quick internet search for "center finder tool" will give you more results to select. Scribe a line in one direction, turn the tool 90 degrees, scribe a line. Center punch and drill away.