Ongoing issues exacerbated after a hike

I’ve got issues mainly in my left knee, either torn meniscus or arthritis. It’s never been scanned though I’ve previously had physio and my last physio said it could be either. I’ve started getting similar issues in my right knee but it’s not causing me issues right now.

I’ve done a lot of strength training in the past and was always advised to build the muscle around the knees. I’ve not done so for a while as I’ve got a pretty physical job and basically, haven’t been motivated enough to find the energy to start up again. However, I want to start again, asap.

I did a hike at the weekend which really gave me a lot of pain. I’m fully aware what triggers pain in my knee but didn’t realise until too late how high we were going so by the time we got to the bottom, I was really struggling and could barely bend it. I also had supports on both knees which did sweet FA. There’s still a little residual niggle and slight numbness in my foot that I believe is connected, though it’s never happened before.

How long should I leave it before starting training again? Or can I start fairly gently now? Any advice would be welcome! Thank you