So, cannot believe I didn't think of this before, but train weak hand, often. I never do, sprained my right wrist last night and I can't even grip a gun if I had too.

Any tips to speed weak hand shooting. Both pistol and rifle?

Lots of practice for mag changes and clearing jams.  Your mind already knows how to shoot, your left hand will not be far behind on trigger control.  Learning to run the rest of the firearm with your strong hands takes the longest.  How do you drop the mag on an AR if you're shooting lefty?

I've shot a ton opposite shoulder and am pretty damn good at it, I have shot a lot of weak hand pistol stuff but it's still never going to be as fluid as the rifle, and it would say it's maximum effective range is 10-12 yards tops.

It's a good skill to have some familiarity with especially when shooting around walls or barricades. Kyle Lamb teach shoulder transitions and Costa teaches a lot of weak hand pistol stuff at his classes.

In addition to just shooting, things like drawing reloading clearing malfunctions are going to need to be practiced with both the rifle and pistol.

If shooting one handed only experiment with:
Putting your normal shooting hand fist into your shoulder, or turning 90 degrees to the target; your new shooting side shoulder will move to center line during recoil taking longer for follow up shots.  Look at the old police shooting pictures for an example.  The recoil comes straight back on your body so your shoulder will not pivot.

If you have NO USE of your normal shooting hand for pistol you can put the mag in, then catch the rear sight on something (belt, edge of table, bed frame, door frame, carpet, etc) to rack the slide.  ARs are fairly easy to shoot with support hand only; however, the controls are spreed out and clearing malfunctions (type 3 especially) will difficult.

Depending on your body type you may not have to buy support side shooting equipment; you may be able to reach around behind or in front of you to access your gear from it's normal position.

Let us know what you come up with; I dislocated a shoulder and had to shoot Dominate side only, and have trained support side also.

You use your index finger to operate the safety when shooting from the left.