I just now mounted (using an adapter) a Canon 50mm f/3.5 Macro lens. I used these sort of lenses in the past with my A6000. What I found extremely useful is a feature Sony calls "focus peaking".
With a manual only lens (like the Canon macro I am using), the camera notices that it does not have an autofocus lens mounted and switches to manual focus mode. You can also select manual focus with an autofocus lens mounted. See below on this.
Press Menu. There are two camera menus on the left. Go to the first one (red). And go to page 13 of 14. At the bottom you should see "Peaking Setting". Enter this menu, find "Peaking display" and change it from off to on. I also change level to "high" and the color to red.
There is a lever on the back of the camera that can be set to AF/MF or AEL. When the lever is set to AF/MF, the button in the center of the lever will toggle from AF to MF and back again.
DMF is "direct manual focus". You let the camera autofocus first, then you get to tweak focus manually.
Tom's Digital Photography Info / tom@mmto.org