Are you from the US?
Yes, you’ll need to get a visa. Why don’t you check out the details at the website of your country’s embassy or consulate? Just google it if you don’t know what the website is. If you look online, you’ll get specific answers to your questions and more than likely be able to print off any forms you need from the official website. You’ll need to get or renew your passport if you haven’t already done so. You will also need to know what part of europe you want to work in.
I’m just saying this stuff off the top of my head. It’s what I would do if I were in your situation. If I said something wrong then let that be the que for someone to step in and correct me.
good luck,
soph

If you are from the US, it will be virtually impossible for you to work in any country in the EU legally for pay, without a residence and work permit, and since you are on holiday it will be impossible to get these. I know there’s woofing and things like that, but most people in your position work black.

So if I wanted to work without a permit, how would I find jobs? And if I got caught, what kind of consequences am I looking at?

They’d likely just send you packing and settle the rest with the people who illegally employed you.