In my case...
# What size pads
Tena Comfort Mini Super (the one with the 5/8 drops) - these should be available to you under a prescription from your urology dept.
# Night time
I went for the waterproof sheet (because the volume of my night time wee worried me somewhat π³) but so far (12 weeks on) I've never needed it.
# Pads per day
Initially 5/6 for a week or two, dropping to 3 and at about 9 weeks down to 2 (1 at a push). Pads have so much less in them now than back in July / August.
Perseverance with the pelvic floor exercises is so important.
I found that I was tolerant of the leaks for a few days (well it was expected wasn't it), then I got a bit down about it (it's never going to get any better), then I found I started needing fewer pads. Now I'm impatient to get down to 1 a day and a lighter pad.
Good luck - you'll get there.