Newcastle can sign any players they want, they have the money and they're in the champions league now.
Osimhen is a good move for them, but Napoli has made it cleared that he's not for sell this season. It will take Newcastle enough money to pull him to the premier league, if he wants to try another challenge this season.
Newcastle Will do better in the league this season than last year, the players are now bound to each other pattern of play, they just need to add three or less players in the squad to make it stronger.
Newcastle is trying to improve the quality of its squad to face challenges next season, the arrival of new players is expected so they can compete in the Champions League. The money that Newcastle has is of course very attractive to quality players, Osimhen will likely have difficulty signing him because Napoli have no intention of selling him. The project built since the change in ownership of the club will make Newcastle one of the teams that will compete in the top four of the standings, if they consistently maintain their performance sooner or later Newcastle will become a challenger in the EPL title race.