10k will not do much good on the grand scale of things. Once you start involving other people directly, the costs start skyrocketing. Be it if you want to bribe politicians, fund a revolution, invest into sustainable tech or just creating a bottle cap recycling programme, 10k just isnt gonna get you far enough. So focus on your own climate impact. I think the absolute best you could do for the most positive net good is to take inventory of your own carbon emissions and replace or upgrade whatever you need to lower them. Lower your heating usage by getting a heat pump instead of burning coal for example. This will depend on how low your carbon output currently is though.
I think “private property” isn’t well defined in socialist discourse and this idea of no private property gets a lot of backlash from some. A distinction between personal and private property needs to be made where one is used to generate capital in exchange for wages and the other is your dildo. The dildo is your personal property and no one is going to take it. A piece of land can be someones private property when they employ you and pay you a wage to work it - you get payed a pittance and they, without work, take the cream.