What to vote now my vote matters?

I’m excited. I have a vote in the Lambeth Council elections, and my vote is going to matter. Although I’m 74, my vote usually hasn’t mattered as I’ve always lived in a safe Labour seat and in local authorities that have been Labour controlled. Lambeth has been Labour since 1971, although with a Conservative/Liberal Democrat coalition from 2002-2006. (My vote must have mattered in 2002, and I think that I must have voted Liberal Democrat. I certainly wouldn’t have voted Conservative.) Now PollCheck says there’s a 60% chance that the Greens will take control of Lambeth Council. It predicts as well that our ward will switch from three Labour to three Greens. What should I vote? I’m certainly not going to vote Reform, a nasty, populist, right-wing party. Although they may do well across the country, they will not do well in this ethnically diverse borough. They are predicted to get only 7% of the vote and not win a single seat. We’ve received no leaflets from Reform. They must know it’s…