I had the surgery and planned to go back to work half time after two weeks. I'm a teacher and at the time the kids in my classroom were very sick. Since I have asthma, my doctor wanted to hold me out of work until my classroom was healthier, so I stayed out for six weeks. Four weeks should be just fine. The lifting and bending should be discussed with your surgeon. If you have concerns and you can manage more time, by six weeks you'll be in great shape.
Different doctors have different protocol regarding food. Mine had me on liquids in the hospital and soft foods for the first five days until I went to see him. At that point, he told me I could eat anything that could be chewed to a liquid, which is pretty much anything.
In the beginning you can't eat much, but by four months or so, you start to be able to eat more. At this point I can eat as much as I did before the surgery, which surprises me. I thought I'd always eat less, and I was fine with that.
If I can answer any other questions, just let me know. It hasn't been that long since I had the surgery, so I think I'll remember most things.
Good luck! You're in a good place to receive lots of information and support.