Phil
Hope all goes well with the op , post op take it easy but keep mobile. Ask for some instilagel or hydrocaine to take home in case the Catheter makes the eye of penis sore. Drink plenty of water, don't get constipation and no straining to pass that first motion. Make sure the Catheter joints are tight, nothing worse than being in your own urine. Snug but not tight underwear will keep the Catheter from moving round and rubbing on the eye of the penis. I attach the night bag tube to my ankle with a G strap.
Treat the catheter as you friend, it will save getting up in the night for a few days.
If you put "ankle" into the search box above it should come up with numerous of my posts about my catheter experiences, including how to shower with a catheter.
Thanks Chris