Credit cards versus cash - how much euro should I have?

You only need a PIN for transactions involving machines, like toll booths, transport ticket machines. Pull a couple hundred EUR from an ATM at the airport. If you need more later, just stop at another ATM along the way. BTW, toll booths take cash as well as credit cards.

Thanks Sam . . .

I like to have some cash on hand before I travel but if you are leaving Thursday it may not be easy for you to get. In that case I'd just get it at an airport ATM. Be sure to notify your bank about your travel plans so you can still access your ATM.

Don't use your credit card for cash as it is a cash advance and subject to higher fees.

The principal places where a PIN may (and is likely) to be needed are transport kiosks (Metro, trains, etc.), and unmanned gas stations. Toll booths don't require a PIN, but you also won't know whether your credit card will work until you try it. So if you want to
use your cc, go to a lane that takes cc and cash (the sign will show a green arrow), and try your cc first but have cash ready.

This is difficult to answer. Do you go to 3-star restaurants? Do you go to bars a lot? What will you spend your money on? When we go to Europe, we like to pay in cash, but the world is increasingly going to the plastic. In Europe, your credit cards are usually quite safe, since the server brings the machine to you, and runs your card in your presence.

I can get euros from B of A next day with Fedex overnight. I like at least 200 to take, getting more if needed. I do almost everything on a card, though.

Fedex overnight? You must have money to burn.

There are both Travelex ATMs (through all terminals) and 2 HSBC ATMs (in terminal 2 next to Baggage du Monde) at CDG from which you can withdraw all the euros you will ever need with no fees (unless your bank charges you ATM fees).

The how many Euros on landing is a FAQ with a lot of opions from Rick Steve's zero:
https://www.ricksteves.com/travel-tips/money/cash-tips

Resist the urge to buy foreign currency before your trip. Some
tourists feel like they just have to have euros or British pounds in
their pockets when they step off the airplane, but they pay the price
in bad stateside exchange rates. Wait until you arrive to withdraw
money. I've yet to see a European airport that didn't have plenty of
ATMs.

to many Americans who are willing to pay for the comfort of having several hundered Euros in pocket going though immigration control.

In either case, notify your financial institutions of foreign travel and follow Rick's advice:
What to Bring

I (Rick) pack the following and keep it all safe in my moneybelt.

Debit card: Use this at cash machines (ATMs) to withdraw local cash,
which you'll use to pay for most purchases.

Credit card: Use this to pay for larger items (generally accepted at
hotels, larger shops and restaurants, travel agencies, car-rental
agencies, and so on). Although Europe's card readers use a
chip-and-PIN system that differs from the one used in the US, it
shouldn't cause much hassle.

Backup card: Some travelers carry a third card (debit or credit;
ideally from a different bank), in case one gets lost, demagnetized,
eaten by a temperamental machine, or simply doesn't work.

While debit cards can make decent backup credit cards (provided your
card has a Visa or MasterCard logo), credit cards make rotten backup
ATM cards because of their sky-high withdrawal fees and cash-advance
interest rates. I'd only use a credit card at an ATM as a last resort.
(Note that an extra credit card can be helpful if you rent a car and
use your card to cover a collision damage waiver).

US dollars: I carry $100–200 as a backup. While you won't use it for
day-to-day purchases, American cash in your money belt comes in handy
for emergencies, such as when banks go on strike or your ATM card
stops working. I've been in Greece and Ireland when every bank went on
strike, shutting down without warning. But hard cash is hard cash.
People always know roughly what a dollar is worth.

My CapOne Visa does not require foreign travel notification. Between the two of us we have 4 debit/ATM enabled chip cards and backup credit cards. Note that while our CapOne Visa is a single account (one bill/statement), each of our CapOne Visa cards have different card numbers. Should one card be compromised, CapOne will only lock the compromised card allowing transactions on the other. (I pay by credit card for my larger purchases when given the option).

My Debit card charges a one percent flat fee. If I take 100 euro, the fee is one euro. If I take 50 euro, it's a half euro. Some cards charge $5 per transaction plus 3 percent, so $100 costs $8. With those fees it saves a some to make fewer withdrawals and carry more cash. With my card, it doesn't matter so I generally keep around 40 to 60 euros on my person, and my debit/credit cards handy.

I like LIDL (bank) and Carrefour (grocery store) ATM's because they ask what kind of bills you want. Any bank that spits out a 50 euro note is doing you a disservice. You're pretty much guaranteed to be frowned at if you use them for a small purchase. I'd much rather have tens or smaller.

You will probably run into some toll booths. I find if you try cards (credit or debit) a second time, they end up working. There were one or two toll booths in Normandie I couldn't get to work after going through all my cards twice. In that case, you need to have cash, preferably in denominations no larger than 20's (tens or lower is much better).

On using mostly a credit card or xcash depends on which country I am in.

In Austria and Germany I mostly use cash, ca 90%, whereas in the other countries, France and England, etc it's about 80% credit card. I carry the needed amount of cash, use the hidden pocket.neck pouch, etc. The bad guys don't know if the amount of cash on me is 80 Euro or 800 Euro, or one credit card or three.