Is there a way you can find out how much tattoos/piercings hurt before getting them?

I don't know about piercings and you would have to ask around like Alize said but it depends on where you get the tattoo. The more flesh around the area, the less it will hurt. Like shoulders, arms, legs. But places like the neck, wrist, and lower back can sting pretty darn good. How good is your tolerance to pain or needles? Ask around and others will tell you things.

Could ask people who have them how much it hurt, but there's no real way since everyone handles pain differently

I didn't even feel any one of my piercings and my tattoo felt like electrified scratches

Not really...as suggested above, it depends on your pain tolerance. The one I have on my chest really didn't hurt, the one on the back of my neck, hurt a little more....the one on my wrist hurt like the dickens and I'll never get another one there....owie!