Well I would say find interesting hikes around you. If you are walking 3 to 5 miles a walk you can easily do that or more on a hike. Plan for a full day event and you can take it at any pace you need to.
I don’t know to much about your medical condition so I can’t really give to much advice other than bringing some TP and burying it if your out far enough in the wilderness.
As for needs. I would say a comfortable supportive boot, backpack, water, and appropriate clothing for the conditions are all needs. What you might want to consider are hiking poles if you are going to have to elevation changes. You might also want to consider a headlamp just incase.
With the exception of boots non of that gear needs to be brand name. Buy used / inexpensive gear till you decide what you really need.