I've thought about it and I think in hindsight it's best that I find somewhere to stay in Penzance, within easy walking distance of the station and town centre as I didn't mention that I have health problems that might require a short rest during the day.
I see what you say. The nearest hotel would be the Cliff Hotel about 75 metres from the station. There may be some B&B in and around Leskinnick Street and St. John Terrace, which is over the road from the station. There is the Longboat Inn, again just over the road from the station, and if they do B&B, I'm not sure and I am sure there are a couple of guest houses right alongside the station and just over the road but they are on the main road out eastwards from the town centre and may be a bit noisy at times with traffic. As I said in an earlier post, the Cliff hotel does have the advantage of overlooking the station and a good view of St. Michael's Mount.
Penzance itself is a bit hilly but not I'd say a difficult climb up Market Jew Street, and then up Causeway Head to the top of the town. The bus station is right next door to the station and there is a tourist centre between the station and the bus station. There may also be B&B and guest houses over the road from the harbour-side too, and still close to the bus and railway station. Hope this is of use.
--- old post above --- --- new post below ---
I was thinking once you arrived at penzance jump on another train and get somewhere else to stay.
The only idea I'd have for jumping on a train from Penzance for somewhere else to stay would be to St. Ives but in view of the fact you mentioned your health problems and needing a rest during the day I'd perhaps sadly rule out St Ives as it is quite hilly and you'd need a bit of a climb, even from the station to get to some accommodation that would be affordable.