APK warm up for basic conditioning. Then, if you want to punish yourself, try the WOD
Getting started - Concentrate on landings at first, then try rolls before you work on your vaults.
Jump Westminster show Forrest and Dan training kids in the UK. The beginning part is inspiring, and watching how they train kids will give you an idea of how you can train yourself.
Your metric conversions are dead on, just short of 5'9", 187 #. I know the conversions, but it's easier to just go online.
Because you're heavy [compared to a 64 kg/ 141# marathoner], take it easy running on pavement. Maybe start with swimming or biking to get your body used to moving again, but without the impact. Walking's not intense enough or high speed enough for what you're going to do.
PK's a lot of fun. I see a lot of 2-7 year old kids doing the basic jumping, landing, and some of the balance things. You can combine play time with your kids and physical exercise at the same time. Quad movement [QM = moving around on hands and feet] is great with kids at ground level. I notice that sometimes QM freaks out little kids [ <2 ].
Down time is NO fun. I twisted my ankle last Monday jumping onto safety mats. It still can't handle the jumping/ landing stresses. I've been walking, biking, swimming, jogged [felt good at the time, but not the next day], and tried jumping .3m into a tree to do pull-ups yesterday [still hurts].
Listen carefully to your body. If you're feeling pain, something is wrong, and you need to fix it [if possible].