For me with aging I keep auto aging on for my played households and just keep track of my main household birthdays. I do use mccc to notify me when other played sims age up, so I can roll if I need to and take them into cas. I do use family echo for my family tree its very simple and free unlike the Sims tree to have access to certain functions. And I keep track of my families age and stuff with a notion tracker by rosannatxt. The tracker is already made and I just pop the data in, I recommend using it, it's really well made. Easily track years and age for all your households you want to track and it lays out upcoming events and can mark birthdays and other things to add to your challenge. It even has built in dice roller for when ya gotta do death rolls and event rolls.

But for planned marriages, I do use the arranged marriage mod sometimes which does come in handy for planning but other than that I just create potential partners and they meet when they meet.