Just click options to do them. Food costs 50 for 100 food. Water costs 50 for 100 water. Bullets cost 50 for 50 bullets. All parts cost fifty for two of that part. You die at 5 thirst or five hunger. Every day you consume 10 food and 20 water. Good Luck!
I took heavy influence from The Oregon Trail, a popular game from the 70's that was meant to teach children what it was like to be a settler in the 1800's.