I think the YouTuber Isaac Arthur has a video (or possibly many videos) on that, but he does so many videos and they’re so long I don’t want to risk linking to the wrong one.

Here’s his channel: https://youtube.com/channel/UCZFipeZtQM5CKUjx6grh54g

The TLDR summary for your quotation is: Complete recycling — with enough energy you can break everything into atoms; Very land efficient agriculture — the cost of glass and metal for greenhouses and desalination is mostly energy, likewise most of the stuff needed to make vertical farming worth considering.

(I don’t remember Isaac Arthur mentioning ocean cleanup, but that may just be flawed memory).

Yep. With unlimited energy you don’t even need sunlight to grow crops, you can use artificial light in any quantity you want.