Cheaper to convert to euros or use Apple Pay?.

I usually find my bank offers the best rate by using my card (or Apple Pay) for most spending above a few Euros. The point is you pay the same overseas rate for your card and Apple Pay so check what your bank charges (usually a fixed percentage) for using your card abroad. Also be aware for small purchases the bank might have a minimum charge for foreign currency transactions, so in some cases it is cheaper to use cash - and of course there will be occasions where you can't use anything except cash. In most cases I have found the cheapest cash by hitting the local ATM and accepting the bank's conversion to Euros - cheaper than buying Euros before I leave home, and it means I can top up when required so I don't have the risk of carrying much cash.

Talking about risk, remember your Apple Pay is more secure than using the plastic card. The risk of card skimming and cloning does not exist with Apple Pay, the details of the underlying card are never disclosed in a transaction.

That depends. Apple Pay does not on its own convert the currency. When charged to your card, your bank would apply their exchange rate for purchases like they would normally do if you used your physical card.

If that Exchange rate is better than the normal exchange rate available to the public, it may be a better option.

Otherwise, cash conversion may be the better choice.

One other point. If you have the choice of making a card payment in local currency or your home currency it is almost always beneficial to pay in local money and let your bank charge its fee for the conversion. The merchant's conversion rate to your home currency is always more expensive.