I want to get opinions about how to cut plastic the easiest best way
vs. what I already did. I had 2 kitchen fluorescent lights that had
custom sized plastic covers or lenses over them. Lets say for now
they each were 18" by 36" long. I don't remember the exact
measurements right now. I had to replace the original ones so I went
to Home Depot and bought 2 new plastic ones but they had to be cut to
size. The store wouldn't do it so I had to lay it on the floor at
home and using a straight edge score the plastic many times with a
sheet rock knife (1 hour work for each plastic) till the discarded
piece would break off without cracking off and which might crack into
the piece I needed.

So for a home diy, is there a better (easier) way to do this? I read
someone who had worked in a glass shop suggested a band saw but I
don't know what that is nor want to spend a lot. Any other
suggestions how to cut plastic safely?

And other than Home Depot, is there other places to buy plastic and
perhaps have them cut it? Any idea what the cost is to cut it?