Make extra saves if you want to. I always have an extra save, just in case someone accidentally overwrites on my save file. Unless you're referring to something else, like saving before continuous boss battles or something.
You can do whatever you like until Chapter 5. By Chapter 5, the endings will start branching off from one another, depending on your shares by the end of the chapter. I'd recommend you recruiting all the goddesses first. Yes, it's a pain to do it the first time. Don't worry. I know you can manage.
Just be wary that one ending, the Conquest Ending, can actually be lost if you don't get it first. It's one of the most surprising endings there. 10/10 I recommend you getting it instead of the True Ending.
Edit: Oh also, put effort into raising your Lily Ranks. They actually play a part this time. You'll be seeing them as requirements for certain plans. Not only that, but there's a certain Lily Rank to be achieved with characters so you can get specific endings. But if you decide to get Conquest End first, there's no need to raise the Lily Ranks.
Also, there are extra events in Chapter 5 that happen with the goddesses. Which is why I'm recommending that you recruit them first before doing any story-related event. After all, some events are lost after you do the next story-related one. And you need to view most of them to achieve other endings. Good luck with that.