Hey Cathy
Many smart people have been caught by this, I thought I was too smart for them because I lead them on pretending to follow their instructions and then exposed them. When they started calling my names and insulting my I was so angry
So you are defiantly not stupid
Here is what you need to do
Check your computer for any programs that you did not install on purpose
This is good to do anyway and remove anything you do not recognise, even if you remove something you are unsure about you can reinstall from a genuine source
Get a good Internet security package (Paid one) the free ones are ok but not good enough for cleaning junk from your computer.
At least you didn't pay them anything, but the fear is that they can use your computer as a "Bot" Robot to do other illegal things on the internet and get you blamed.
Mcafee
Norton
AVG
Don't know where you live (Don't need to know) but a good Internet security will cost you less than £50 or $50
You will mostly get a free months trial which will help you to clean your computer and you can pay for it after that
I know it seems like a lot of money, but look how much you depend on your computer
If you need any more advice, just ping a message back here, lots of good people here will help
Paul