Time and time again is see people struggling with KS budget and cost planning. I've created many videos related to the topic, but I decided the best thing to do would be to do a full walkthrough of an example budget. Watch the video for full details. I hope this helps!!
Budget Sheet: https://docs.google.com/spreadsheets/d/1_-5kMaEAEemBW0aLHhS1LYauM77X2ja4pHQdm3KOZi4/edit?usp=sharing