And you don't need to be a hardline child-free bicycle riding vegan hippy to make a difference.
Reductions in all those things will make a difference. Have fewer children. Choose to own a more efficient car and choose to drive it less. Reduce your long distance and international travel. Eat more plant based food and less meat and dairy. Eat more locally sourced and seasonal food. And there are other lesser impact things too: live in a smaller and better insulated house. Prioritise efficiency higher - choose to buy more efficient appliances. Use low energy lighting. Choose to live near where you work/play/socialise. Choose lower carbon impact hobbies and recreation, perhaps a sailing boat instead of a ski boat? Perhaps athletic sports instead of Nascar?
At a bigger picture level. Vote for the planet, appropriately prioritise climate change policies in your voting choices (and with two party politics, this can be difficult to do, don't vote in a facist just because they're a treehugger, but try to also not vote in your own self-interest if that candidate is deeply in bed with the fossil fuel lobby). Focus your career towards ecologically sound companies/industries where you can - actively seek and choose jobs with climate change in mind, if you have a choice between two roles consider carefully before jumping to the slightly higher paid fossil fuel job. When making or contributing to decisions at work, ensure consideration for climate impact is brought up where appropriate.
And make a noise. Be publicly unsatisfied, even if you have no solutions. Let other people know you care, even if you can't see any real way to make a difference yourself.