I shall be at a wedding in Norfolk that weekend as otherwise I might be interested. Having said that, I joined the big march a few weeks ago in support of Palestine and spent well over an hour standing around outside Bush House in Portland Place before we started moving. Walking is fine, cycling is fine, but just standing about buggers my knees. I'm old enough to have been in the massive CND demos of the 1980s - indeed, my brother and sister took part in the anti-Vietnam War demos of the 1960s, but my mum wouldn't let me go because she thought 14 was too young.
Good luck with it - it's the Cause of our Age, even though our politicians are in bd with/financed by those whose interests lie in denying a link between climate change and the burning of fossil fuels.