What flowering tree is this and can I grow it from the seedpods and what exact steps should I take to do so?
Should I take the green or dry brown pods?
It's a Senna, most likely Senna pendula, maybe var. glabrata. Depending where you live, growing it deliberately might not be a good idea because it's classed as an invasive weed in many parts of the world. If you do want to grow it, collect the ripe (brown) seed pods, extract the seeds and start them off in pots,though to be honest, its so invasive you could probably just throw the ripe seed pods on the ground somewhere and they'd do it all themselves; this type of seed pod, once its fully ripe, brown and dry, will usually twist itself open and fire its seeds all over the place relatively violently. Information here https://keyserver.lucidcentral.org/weeds/data/media/Html/senna_pendula_var._glabrata.htm