Multiple posts types connected to one parent

Hi, I have been looking around, but due to only having been using timber for a week, the answer doesn’t seem very obvious. I understand there is a parent child feature, but im wondering if someone could give me some more information on this. I’m trying to create project pages, however there is two much content for one page, so it needs to be split in to 5 pages. They will need their own permalink structure, but i can’t figure out an easy way to do this other than i guess sub categories?, so i was wondering if there is a way to group 5 different page templates to one single project, wouldn’t even be sure how to go about putting something like this together on the admin. Any information on where to start reading up about something like that? has any one on here done something like that before? Any help is appreciated.