Inventory Sheets

I am a newbie here and with vba. If anyone could give some guidance, I would be very appreciative. I am looking to create and Excel file with 3 sheets, Check-In, Check-Out, and Master List. Check-In and Check-Out would be where new items are logged in or out. Once an item is logged in, I want it to auto-populate in the Master List sheet as well as summed if it is an item type that has been previously received. When an item is checked-out I want it to be subtracted from the Master List. If there is no item to check out, or if it is getting low, to spit out a warning.

Thanks in advance.