I go to rock steady boxing and find it helps a lot. I had to lay off for 8 weeks after getting a pacemaker and it got noticeably worse. Got better after I was cleared to resume.

There is a physical therapy program called LSVT-Big that is specifically designed to help people with PD who have issues with walking. It is very intensive, but effective (4 days a week for 4 weeks). Rock Steady Boxing is also aimed at Parkinson's and is very popular. Yoga and tai chi can help with balance and strength.

Leg and core strengthening excercise. Most of them can be done layuping down or sitting

I live Pilates. I go 3-4 times per week

Boxing is great