So here we go!
Rather than using scissors to cut out your lampshade I highly recommend using a rotary cutter and a steel ruler. This is the ruler I use which, most importantly, has a raised cutting edge on one side to protect your fingers. It is 50cm long so not too unwieldy1
I use an Olfa rotary cutter, identical to the one shown here. They are super sharp which is fantastic for cutting the PVC and of course fabric, but beware of your fingers!
And eventually you will need replacement blades for your rotary cutter, so these are the ones to fit the cutter shown above.
The most expensive item here is the A1 self healing cutting mat. I did start out with a smaller mat but it is really much easier to use an A1 sized one as it is big enough to fit your lampshade on to make the cuts without having to move everything around umpteen times.
So there are all of the tools you need to get started - happy lampshade making!