Every cheap country (Vietnam, Nicaragua, Thailand, Bali, etc.) will have a hodge podge of backpackers, ex-pats, retirees, etc. Enough locals will speak English to support providing necessities and socialization can happen with the other ex-pats.

Working there is a different story, but generally you don't want to work there since the reason they're cheap is that the people are poor. The local jobs are low paid. The trick is to be able to work remotely or more rarely as a well paid employee of a foreign company.

Language is not a requirement to live/work in Croatia. There's a huge expat community in Croatia, I have met many Canadians and US citizens who came here and got their job because of their great English. Yes, working as an English teacher, or translator, or any language related job is a bit boring, but for tech people there's a huge demand and English-only is perfectly fine.

Food has labels in English, restaurants and everything else, because of tourism, are very English oriented. It's a great place for foreigners.

I've been to Croatia a few times. It is very English friendly. Even a lot of the local TV was often in English. Croatia is a great place, and I highly recommend visiting.