Re: Training when you can't train (injured newbie)?
Walking. If you live in a community where you can go for hour-long walks, go for it. See if you can get up to 4.5 miles/hour and keep it there. Do that daily. Do it with someone else so you can both benefit - whether that's a partner, husband, son or daughter, puppy, friend, whatever - it is always better with someone for more than just safety reasons.
If the dojo is about 30 minutes' walk away, walk there, watch training, walk back.
All the other stuff about being aware, doing core/exercise ball work, mirroring the movements being done in the dojo, observing practice, doing your physio, etc. are all good too. In calgary our sensei had a shoulder separation and spent our morning training sessions at the side of the mat advising while doing an hour of shoulder exercises (flex, extend, rotator cuff, abduct, adduct...) and came back rock solid.