Agree with the previous post on extensive use of help menus, forums etc. There’s tons of info out there. Then go with presets or what others have posted for similar equipment to yours, then refine from there.
Don’t worry too much about getting every detail right off the bat, I think that’s neither possible nor really desirable. Best to refine things like “trub loss” over the course of one or more batches (many people say 3-5 should do and I agree with that, it’s five for me whenever I change equipment). For example, trub loss may vary with the amount of hops, form of hops (pellet whole etc), whether you use bags or screens to contain vegetive matter or not, etc., so you’ll need to measure how much you’re actually losing a few times then go with an average, or if you’re really anal (not necessarily a bad thing for a brewer so not a slam) you’ll set up different profiles for different styles - a double IPA hop bomb and imperial stout might fit one, while a basic lager or blonde ale could fit into another.
You should measure your dead space and things that will affect your mash water volume prior to brewing the first time as those don’t change and will have a significant impact if you’re brewing all grain. Similarly, if you have a spout on your kettle you may lose a couple quarts / liters Standard wth each batch due to its placement and the fact that a lot of bad stuff settles to the bottom (whirlpooling with a spoon can lessen this significantly). So there are some things you can control or affect and others you can’t.
I have six liters of space under my false bottom in my large tun so I have to add 6 extra liters of hot liquor / mash water to get the proper water to grain ratio. If I didn’t take that into account I’d have super thick mashes that would not extract fully or properly so my numbers would be way off. That’s the kind of thing you have to worry about prior to or during your first brew. Everything else you’ll learn as you go and have a lot of fun doing so!