When I think of “boots” I think hiking. You may only need a very good shoe or ankle bootie, with very good arch support, for walking. I did 10,000 steps everyday in the hospital in soft soled shoes. You’re taking it to the next level - outdoors.
Thick absorbent socks, long sleeved t-shirt as first layer, then tops/jackets you can peel off if you get warm. Definitely pants/leggings.
Walking stick if you have vertigo to stabilize yourself. For more of a workout-type walk there are Nordic poles. Check into that.
Learn to BREATHE properly as you stride and swing your arms in sync for maximum effect. That is so important.
Cheers!
USA Gundy