I tried gentoo a while ago and couldn't figure out portage, but that's on me... The reason i switched to from standard arch was just because my pc took 3 miniutes to boot (from nvme) and changing my init sys to runit solved my issue. I'd love to actually figure out gentoo someday though
There's a support channel on irc for things like this. Also portage is just a better pacman--it can do more and thusly a time investment is necessary to be in control of your hardware