57 yr old newbie? or oldie?

Just starting out....yikes.....i know, i know..... been sedentary for awhile. RA and some not so good knees. Man! they just don't work, bend, or flex. I say....give me some new ones! But i got up today and said...that's it, i cannot keep on gaining weight like this.....I got to do some kind of activity. So today is my biggest accomplish ever! half an hour jumping on the trampoline and stretching. It was a good 25 min workout! Thanks for reading! And good luck to you all that are working on themselves! High five!