Thanks for all the helpful comments. Sadly I don't have any B&W undeveloped film to practice with, nor do I have a working SLR camera any more.
But I keep finding more unprocessed C-41 films around the house so by the end I will be well practiced. Have been testing different volume water baths and I can achieve and maintain 38C to within half a degree for over 5 minutes even without topping up, and no water heater. My two digital clinical thermometers are very useful at that temperature.
My 'new' vintage 35U seems to be in good working order, is undamaged and seems very easy to use, though I don't yet have the chemicals. To simplify matters, I am thinking of ordering initially a digibase pre-diluted solution 3 x 500 ml C-41 kit but as I intend to process initially only one film a day, I don't know how long the solutions will remain usable (if stored in sealed 500ml bottles). A month would be fine, but will they last that long?