No idea if some of the advice above is good in general. For me, at 68 probably at the more senior end of RP, here's my experiences:
1. Sleep in hospital was pretty much non-existent, but it was only one night and my bag was definitely not in range to put on my headphones. Maybe those who go private have more helpful night staff, but my experience is that on the NHS they pretty much ignore the patients as much as they can. Most appear to be studying.
2. It definitely helps to not be pushing your stools, but the biggest factor in this is to be moving asap - I got moving as soon as they let me and was doing 30 minute walks as soon as the catheter came out. That said, I took my course of lactulose because I tend to suffer from constipation anyway.
3. I also found that despite the catheter I felt the need for the toilet on the way home (a 1.5 hour journey for us, as our local RARP surgeon left our closer hospital just before the operation). Emergency stop at petrol station saved the day.
4. Really not much pain - I took the Paracetomol and Ibuprofen prescribed for a few days, then dropped the latter (caused some indigestion) and then the former, with an OK from the Cancer Nurse.
5. Never had a leak at night and never took any special care of the bag, just went in a bowl on the floor. Have had bad bladder reaction to general anaesthetic thrice previously, so a bit blase about the catheter; not found the need to pussyfoot around it much. Great relief when it comes out, of course.
6. Scars are nothing, at least to someone that has had proper carve ups (my melanoma scar is about 8" long and not pretty, for instance).
7. Bruising comes out over time - don't be surprised when your balls suddenly turn black & blue. It all goes.
8. You can get some continence pads/pants in the free pack from this site. They are actually quite heavy duty, so are almost certainly enough to get you going. If you need more, any decent sized supermarket is likely to have some - although likely hidden in female products! Otherwise Incontinence Choice have a very wide range at reasonable prices that can be delivered to your door. I was able to switch to the light pads quickly so never needed to buy any more of the heavier pads. Of course YMMV.
9. Definitely trackies are the thing post-op, but any reasonably loose trousers are OK with a catheter - whatever you feel comfortable in. For underwear, I used trunks, which offer support but are not too tight - I wear them a size up (in waist terms) anyway.