I’m always amused by the way people say they’ve won something on Ebay.
OK, so you’ve bought a plotter. what’s a P-cut? Is it one of the chinese things? Presumably it will come with some software or you will have programs to drive it.
To test it send some shapes of known size and cut them out. You can then measure them to check scaling. A rectangle will show the quality of corner cut and a circle should be that, not elliptical. Cut some large and small text, serif and sans serif and look at the cut quality in terms of ease of weeding, square corners etc. Depending on your software, check panel cutting and overlaps to ensure they work.
If that’s all OK, start earning. If not, start cursing!!
Peter