Anyway if one of them gets it, the chances are very high the other will too…
The other will in such scenario get it too. 100% chance.
Go shopping when it's not crowded. Or where it's not crowded. Prices might be higher, but try to shop as much as you can in small local shops. Avoid big trading centers.
As much as you can use your card, not cash.
Before touching your face, always do wash hands. Even if you didn't touch anything previously. Normal soap will do, no reason to buy whatever disinfectant whatnot.
Try to be at least 1m away from other people.
No lollygagging all around the world. Stay at home. By that I don't mean the dump of a flat you're living in, but your neighborhood. Vacation in Zimbabwe, Zanzibar and Bangladesh? Postpone it for next year.
No parties or family dinners with numerous people! Socialize rationally, with only a few people around. Tradition is good, but sometimes like now we need to postpone it for next year. Your folks who live 1000km from you won't die if you don't visit them for two weeks. Use Skype or something similar instead.
I always suggested people to go out, explore and grab a coffee somewhere new. Till this outbreak is over with, go for a coffee only where you usually do. Turn off the adventuring mode for the time being.
Your BFF or something just arrived from Moon or Mars after 856378467843 years and wants to meet with you face to face. Politely refuse till they pass the selfisolation of 14 days. Okay?
The boss threatened you: if you don't appear at workplace you'll be fired. Choose yourself. Penniless month but staying alive or barely enough cash for normal living you get at that job that comes with a death risk.