I have only been loading for 40 plus years....... and have never washed brass yet. Wipe it off with a rag. It doesn't matter one whit if it has some dark color to it. The only thing you need to worry about is that it doesn't have any mud on it from being dropped on wet ground. If you put your fired brass in your pocket, or a cloth bag and it rattles around a bit by the time you take it out to load the bag has rubbed the smoke off the brass.
I loaded for 35 years with no tumbler. You don't need a tumbler. Yes, you can make the brass shiny with one, but shiny brass is for looks only.
I also loaded for over 30 years with no calipers. Nice, but not necessary.
You do need to verify the powder charge. A scale is a must. As RC mentioned an overcharge can be catastrophic.
You will need some way to seat primers. Does the hand press have a primer arm included?
