ACL surgeries coming up soon

Hi, hoping I can get some advice on what to do now and in the future -
Background - I have had ACL reconstructions on both knees for separate injuries around 5 and 6 years ago. I have since damaged my right knee again through sports (unsure of when exactly it went). Eventually went to a doc, had an MRI (torn ACL, damaged MCL and MM along with cartilage damage and anterior tibial translation. Got referred to a specialist who says I need 2 surgeries, the first to fill the hole left from a disposable screw on the previous repair, and the second some time later to actually do the repair.
Current - I have been sent away for 6 weeks to try and strengthen my knee before returning to the specialist to set up the surgery which will likely be another 8-12 weeks or so from then. Then 6-12 months after that, the second surgery.
Me - I am 5'10", 240lb (weight gained while unable to play usual sports), with quite a bit of muscle loss on my legs from lack of use. I have an active job (chasing 3-4 year olds around a nursery) and have joined a gym to try and get myself sorted!

I'm hoping someone can point me in the right direction of the exercises that will help strengthen my knee, lose weight and not risk further damage to my knee. So far at the gym my usual plan is 10 minutes on a rower of bike as a warm up, then leg weights (3x10 reps at 75kg on leg press, 3x10 at 45kg on leg curl, 3x10 at 35kg on leg extender, bit of arm weights to fill time and then repeat leg circuit) then 10 mins on bike or rower again. I have absolutely no coordination or ability when it comes to treadmills or crosstrainers, so avoid them like the plague! I am trying to go every night since I have a limited time schedule to get sorted, my leg feels ok, but want to make sure I am going in the right direction or if there is anything I should change to help (more weights, more bike, different weights/reps etc.)

Thanks in advance
Matt

Since you have damaged ACL, MC and MM, you should avoid knee exercises which need you to flex the knee.

Static exercises would benefit you the most. Exercises should be done for all the muscle around the knee. I suggest following exercises.
1) Knee press: keep pillow beneath the knee and press it by the knee. Hold it for 5 sec, repeat it for as many numbers as you can.
2) Straight leg raise.
3) Straight leg raise in side lying.

Hope this helps you. best wishes.
Everything Physiotherapy

Ok great, thank you for your advice!