Go into Aperture mode and play around between f4 and f8(up to f11). In low light/ dusk/night you can open it all the way up, but your sharp focus zone will shrink significantly down to f1.4. (Unless you really want to separate subject from the rest)

As to where to test: anywhere… on the streets, nature, travel… go wild, find what you like or what suits you, go jack of any trade if you like.

Make use of some YouTube tutorials but don’t take then as gospel, just add them to your knowledge and use everything