Can you do this:
At the same time? I don’t think I could. I’d be tired all the time, and I don’t think I’d progress on either very quickly if at all.
Do you train in the gym at all currently? I’d start with a 3 day program if you aren’t currently doing anything. Ease into it. Better to start easy and stick with it, then burn out.
You could try starting strength as a starting point. You won’t be able to run that very long (or at least not likely). Progress is fast with it, but most can’t keep that up very long. Many have good long term success with 531.
I may sound snarky, but it’s not my intention. I’ve tried multiple mountain bike sessions and powerlifting at the same time. It’s a lot to handle. Finding your volumes for each that allows progress on both is going to take a bit of experimenting. Getting strong isn’t easy when that’s all I am focused on. I am a lot stronger, but even if I were to add in 5 hours of hard training on the bike, I’d expect a dip in strength.