Traveling with some cash and need to exchange for euros, is this best done at the airport? I know that banks basically don't do this unless you have an account. Can anyone advise?
Just get a small amount at the airport, to cover immediate transport / food needs.
You'll do better at the competing forex shops in town.
I wouldn't.
Best is to use your ATM card. Even if you're already here.
F/X shops charge quite a bit and if you do use them your next post will likely be complaining about the horrific exchange rate. For smaller amounts don't be surprised to lose 20+% between exchange rate and fees.

So then it depends on the amount of cash you change? if you exchange more the rate lowers? I understand that the ATM is a better rate, yet I have cash...
The problem is they start with a fixed fee. They then tack on a bad exchange rate. If you exchange multiple small amounts you'll get hit by the fixed fee every single time.
But really unless you're here with absolutely no other choice don't use them.
Yes - ATM cards are better, and larger amounts are better. But I worked on the assumption that the OP had cash they wanted to change.

Yes, you are correct. I will have to bite the bullet, but I will try and do so only once!