Ok, so I think your confused between the aperture and focus. Focus defines the distance away from your lens at which objects are in focus. Aperture defines how tight or narrow this "oobject is in focus" range is.
To achieve a more exazzurated bokeh, you need to have a higher aperture number. As a side note, a larger aperture (lower f number) gives you a faster shutter speed. As always, have you ISO set to as low as you can while still keeping your shutter speed high enough to freeze motion - which is usually desired in portraits.
Now, I find it odd that you say your lens does not have manual focus... Usually if anything, a lens will lack autofocus - not the othe way around. Either way, I always use autofocus because I trust computers more than my eye
To try these ideas out, have a subject around 0.5 m from your lens, with a backround further than 3 m away. open your aperture up as wide as you can and focus on the subject. This will give you the largest bokeh that your lens is capable of. Now, take the picture again but close your aperture a bit (higher f number). You will see that the bokeh effect is reduced.
Hope this helps!