Welcome, Tracy!
1) Yes, week in the life (you'll see it abbreviated often to WitL) can make a great first time experience! If you come for the weekday portion, everyone is in a much more relaxed state, which gives you the opportunity to ease into your character and make connections without worrying about people being pulled away. There's also fewer people than the weekend portion, which might sound like a detriment, but depending on the size of the parlor larps you've attended you might find it less overwhelming to meet people in smaller groups.
If you're just coming for the weekend portion, it's run in a standard event style, so choosing that weekend over any other wouldn't be much of a difference (except there are probably more tasty leftovers that people are trying to get rid of from all the cookouts in the days leading up to it

)
2) Whatever you show up with you're considered to have as "basic steel" versions. You can get an item card for them at check-in if you'd like something written down to help you remember damage or armor point values. The physreps (the prop you have chosen as your weapons or armor) still need to be evaluated at check-in for safety either way (TBH any marshal can do this at any point, but there's better lighting and the item cards are more easily available at check-in).
3) Hold off on that for a bit; our tech team is about to release a new character builder to go along with some of the rules patches. This will be completed in plenty of time for a May or June start for you