I didn't start really training until I was almost 30. I'm older now . I have joint issues all over (to the point where I think I may have some underlying condition) but other than some minor hyperextension of the elbow, striking has kept me pretty injury-free. As a frame of reference I hover around 225 lbs, mostly north of that!
Where are you located? To me striking is like golf – the movements are basic, but should be done precisely and can be mastered over a lifetime. As long as you start with a solid foundation, to include proper wraps and gloves as mentioned above, I think you'll do just fine.
10 hard rounds on the heavy bag is a brutal full body workout, with (IMO) excellent real-world benefits. If you can find a friend, padwork is great too.