Practice Manual Focussing
Ever see the credit for "focus puller" in a film's credits? That's a single person's job, just to keep the camera focus where it should be on a moving shot (or even for changing the focus point at the right time in an otherwise static shot).

Usually the shot would be blocked out before hand, and they would work out exactly where the object of focus is going to be throughout the shot - they know in advance exactly where the focus needs to be at what time, and that person will make those focus adjustments as the shot is filmed, while other independent operators are moving, zooming, tracking, etc the camera. If your camera has the ability for the focus to be remote controlled via a pre-programmed sequence, that is also an option (usually you would remote control the camera movement as well, so it is all in sync).

Trying to manually track the focus while you're also operating the rest of the camera will be difficult to achieve accurately. I would consider breaking up your shots if possible, and cutting between more static shots. Otherwise just rehearse the shots as much as you can - it's not that it can't be done, but there's a reason films have an independent person working on just that task.