I found a Generations Challenge. Is that the one you are talking about by Gyaanipedia? If so, I read through it and that challenge isn't overly challenging with the amount of requirements, etc, so I think you could probably just wing it and be ok.
The rules state that you can only use one anti-aging potion and that aging should be on, so if you turned off aging in university, it would be against the rules, so I guess it depends on whether you care about that. If you are interested in sending your sims to university, it's still worth it imo. If you get the distinguished with an A, they can start at level 8, with a huge pay boost. I would take most of young adult to get there anyway, and with the potion of youth, sims would still have 2/3 of their adult lifespan left.
I don't play on console, typically, but I have before. I couldn't offer advice though on how to handle your saves.
Spa Day is my favorite game pack, and I use it in every single game I play, but I can probably count on one hand how many times I actually went to the spa itself. It doesn't matter how poor my sims are, if they have $50, they will have a Lavender foam bath every morning with peaceful patchouili incense lit. I tend to always do the 'happy' bath so I can change emotions easily throughout the day and it will always benefit. The massages and yoga also give long lasting moodlets as well, but admittedly, I personally don't use them as much.
As for lot traits, I almost always pick home studio, study spot, and peace and quiet.
Clubs with Get Together are massively OP. I stopped using them personally, but if you are struggling skilling up, make a family club and buy the perks for whatever skills you are working on. Tiny homes are another thing that is super op. It could be a great way to start with a single sim blank from cas. Eventually, they get unreasonable unless you just want to have a bunch of tents in the yard or something. I also heard of a way you can cheat it, but I personally wouldn't do that.
Take advantage of toddler, child, and teen years. If you are able to get to tip top toddler (max all toddler skills) that's a 25% boost to all skills. For thinking, watch. For imagination, have a parent read to them. For movement, use the slide if you have toddler stuff, if not do the play interaction. For communication, have them talk to the bear. It generally takes me 2 days on a normal lot to get toddlers to max skills. If you know that a certain heir is going to be in the painter career then do those specific childhood aspirations that go along with the skills they need. For example - master of the real is logic and painting. Have the child do the creative and mental aspirations. Or if you are able to complete them all, which is possible, do that. They will have so many aspiration points that is going to give them such a head start. Put the kids in scouts, have them get to unicorn scout (the top level of scouts - all badges) before they age to young adult. With teens, if you have plans for them to go to university, check the guide for the major they are going into. Have them complete the skills necessary for them to be able to get the distinguished degrees. Also, I usually have all my teens to at least be responsible, but I also like them to have controlled emotions character values.
The proper emotion matters, especially if you are going for quality. It also helps skill gains, obviously.
Don't underestimate the aspiration rewards, some are really powerful.
I apologize is this is known advice, I don't know how versed you are in the game. Anyways, I hope that possibly I gave you some solid strategies to help you in your endeavors. Good luck!
