It's worth having a try at a couple of different options to see what suits you. At this point you won't have much of an idea of how much, if any, leakage you will have.
As a safety measure lay in some pads just in case - probably Tena Level 2 or the Abri-man equivalent would be a good guess, but don't buy too many just yet.... (NB Other brands of pads are available. I don't have any personal financial interest in either of these!!! I have just used them as examples.) Both are stocked in Boots so easily available. If you are relatively dry, go down to level 1. If you flood the pads, go up to level 3. BUT if you have been treated by the NHS, you may be given some basic pads anyway after catheter removal. You will have plenty of time while recovering from the operation to make your mind up as to what is best.
From personal experience, pads are probably the best to start with. For extreme leakage, disposable pants are an option (e.g. Depends) - fine provided you can change them at home. However trying to change them in a toilet cubicle while away from home is a logistic nightmare, even when the floor is dry.
Following on, there are lots of options, but I don't think you need to worry about them just yet.
Please give yourself time to recover after the operation. There is no rush.