JP10 absolutely right, spend a week for reading some articles and books, and you will create the best programm or remake some from literature, for cos only you know can you do something or not, maybe coach can be usefull for you to control and correct technique but usually guides on youtube is more than enouhg.
And about your joints, my sister in London also has bad joints because of rowing in professional team, but she still go gym and do hard training cos one of the main points in fitness is a technique. If it's correct your joints are in safe.
And if I am not mistaken she often do yoga and pilates she says that it it helps her joints, so you can try some of this. She's going to this
studio, and once when I were in london she said me that I must go there, and wanna say it's really good thing to relax and stretch out.
In any case good luck and remember the main point in any sport, when start don't stop
