if you can't reach a 9th, you can cheat and use your left hand to play the lower half of it (in the specific instance of measure 8 for instance). this won't work in other instances where you need to be doing something far away with your left hand, in which case you'll need to either leave out a note or roll the chord. if you decide to leave out a note, drop the one which is inessential, ie not doubled with your other hand. in measure 16, for instance, you have several possibilities depending on how you pedal, as you may be able to use your left hand to play the RH B, drop the RH B, or very quickly roll. of the above, the easiest is to drop the note, but it significantly changes your sound.
some editions specify the use of the una corda (left) pedal, others do not. if you are using it, you should keep it depressed until specifically told not to, which in this instance would mean keeping it depressed throughout.