Got fat and now want to loose all that fat.

Hey guys. I used to be really athletic during my teenage years. My height is around 178 cm and when I was 20-21 my weight was around 70kg. Due to some job constraints and unhealthy lifestyle and ungodly work hours I got out of shape and gained. Currently I weigh around 105kg. I can still run 5km and do boxer skips for 5 minutes straight and can repeat 2 sets like this with 3 sessions per day. But my knees hurt like crazy.

This is how my current routine looks like -

Evening - 6 km walk (in 1 hour)

In between I accomodate 3 sessions of jump skips.

Weight training - 3 days a week (push, pull and leg day)

I have recently read that running can impact my knees long term and I am worried about this. So I have stopped running. And I am even thinking of quitting rope skipping before I reach a safe weight.

Is it true that knees can worsen with running and rope skipping?

How can I take good care of my knees and what is ideal weight at which I can start my runs and start rope skipping?

Any help is appreciated. Thank you.