For emails the best way would probbly to just create a disposable email adress and go around to a bunch of sites (like blog sites) and sign up for their stuff, i.e newsletters and promotions. If you want you can read their privacy policy to gauge how likley they are to sell your data. I would also have a look at https://mailbait.info/ although I have never used it so I can’t tell you how good it works.
As for popup scams I would have a read of this guide The Ridiculously Easy Guide To Finding Each and Every Scam Number, however popup scams are fairly rare these days as they are they are ridicuosly easy targets and usually get shut down very quickly.
Hope it helps