I suggest not to complicate it,

use this free server, which is currently one is the most popular and backbone of Nostr:

wss://relay.nostr.band/

and ignore the rest for now, there is a lot of pushing and noise from Nostr developers and Nostr pseudo influencers to move to paid relays, which is normal, money talks, their grants will not last for ever and they need to monetize, most of them have invested in paid relays, which ironically are all centralized censorship machines LOL! you can't make this up, but hey! you won't get gay porn bots or other nasty content which apparently is viral in Nostr now... just mute them and block them, easy, no need to get into a gestapo relay and pay for it.

Once Nostr goes all tyrant (there will be signs... errr already there) most of us will go back to Mastodon or an alternative libertarian truly decentralized option,and for the daily non decentralized, X, currently is not an easy answer, but projects like Session Messenger could be the answer, monetization matters to maintain the network, so does privacy.