Welcome and great decision, you will see alot about exercising to help in the first weeks, and well that achilles looks like a hinderance, so I will also offer up to keep yourself busy with hobbies.
Put together puzzles, models, be creative with little tasks at the workbench. As if you can't get to the gym to keep your body busy, at least you can keep that mind as busy as possible and occupied with some good, constructive.
I do some amateur leatherworking and did a little project when I was 3 weeks in, so it is just whatever it takes.
will quit with you today.