new at rk3588 | newbee questions

[lblabr]

i bought a used tv-box power by rk3588 to play around with that (H96 max v58), with the goal to get a linux system running on it.
i dissasambled the box and there are jtag pins, so i may see the bootlog

I'm starting here:
https://github.com/ncravino/H96_MAX_V58/tree/main

i already compiled things for openwrt routers, but they were supported by the build process. i'm open to learn ;)

i do have some general questions:

1. is it posssible to use an image of another device for basic function and from there go ahead?
2. what are them main steps to build an own image (point to the right doc would be great, may be for dummies)

any advices (links, hints) are warmly welcome

thanks a lot

Lars