Travelling spending money?

100 euros a day is more than enough dude. If you have that you will be fine.

You can soend only 20-30$/day if you want

Take very little cash, just enough for daily expenses...certainly not for ten days. Why? Because you can't afford to lose ten days worth of money.

What you do is use the ATMs that are just as prolific in Europe as they are in the US. When you need cash, in the local currency, you simply go to the nearest ATM and make a withdrawal.

Almost all ATMs are universal. Which means you can use your same US debit card in Europe to make those withdrawals.

I personally never carried more that $100 equivalent in my wallet on any given day in my travels to the UK, Italy, France, and Norway and always found an ATM nearby where I stayed. I relied heavily on credit card purchases.

You're not 'going around' Europe in 10 days. You're only going to be able to visit a few different places.

But yes, about 100 Euro a day would be okay for meals, admission to museums and sites, and the odd souvenir. Do not bring cash, check with your bank that you can use your ATM card there instead, so you can get money directly from your bank account at home for a small fee. WAY safer than bringing cash.

$100USD a day