S.B.
I agree with beginning in water.
I am an avid swimmer and for me....it's the best exercise. No sore muscles afterwards and I'm so relaxed.
There is something so calming about it.
When my daughter was little, I had a membership and we swam every night after I got off work. I was so tired, but the swimming made me feel wonderful and I slept like a baby.
Years later, I had access to my own hot tub and swimming. It's definitely wonderful.
Water can give you a very calming and and non impact form of exercise. I loved doing underwater back flips to tone my tummy. Never a sore muscle.
Best wishes to you!