ATMs are common; credit and debit cards are widely accepted.
Tipping has become more complicated, with ‘service charges’ increasingly added to bills. In theory this means you’re not obliged to tip. In practice that money often doesn’t go to the server and they might make it clear they still expect a gratuity. Don’t pay twice. If the service charge is optional, remove it from the bill and pay a tip. If the service charge is not optional, don’t tip.
Generally, waiters in Western Europe tend to be paid decent wages. Bargaining isn't common in much of Europe, but is known in and around the Mediterranean. In Turkey it's virtually a way of life.