@Nottinghillbilly

There are 2 trains an hour from Crystal Palace to London Bridge on Saturday at 23 and 53 past each hour but the routes goes "round the houses" and takes 28 minutes to get to London Bridge. This route doesn't run on Sundays though.

Alternatively there are trains from Crystal Palace to Victoria on both Saturday (4 trains an hour at 08, 27, 38 and 57 past) and Sunday (2 trains an hour at 26 and 56 past). The journey time is also 28 minutes.

Best place to check is:
https://www.nationalrail.co.uk/ or the National rail app