Ask for a mask! Many places have them for free. Always wear a clean, dry mask.
Soon stores will be handing out better masks for free. There will be 3 for each person.
The thicker, safer masks are called N95 masks or KN95 masks.
The medical masks are very good, but throw them away when they are dirty.
If you want to wear a cloth mask, it is safest to wear 2 masks, a medical mask & a cloth mask.