I'm doing a guide/walkthrough, but it's backer only (https://www.patreon.com/indivi). You can also check out this fan made wiki: https://ldp.fandom.com/wiki/Lust_Doll_Plus_Wiki
In addition, there's two places ingame you can get hints: The logbook tells you about any tasks you have outstanding, and there is a seer in the slums that'll tell you about any NPCs you have yet to meet!