When you shop don't touch things, observe them to choose them, then grab only the one you want.
Wear an effective mask (and correctly! Otherwise it's useless) if you need to go to an area with a lot of people, if possible. Gloves can help too. Keep at least a 2m distance between you and others.
Lastly, despite the difficulty of remaining calm and happy, don't forget to remain polite and friendly with others, it helps everyone go through the crisis and it is important to remain civil despite the situation.