ATMs are common; credit and debit cards are widely accepted.
Service charges are 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. Don’t pay twice. If the service charge is optional, remove it and pay a tip. If it's not optional, don’t tip.
Tipping isn't such a big deal in Europe as it is, say, in North America. Small change usually suffices in Italy or Spain. Between 10% to 12% is common in the UK. Unlike North America, credit card machines generally don't have in-built tip requests meaning you'll have to leave your gratuity in cash.