I just inherited my Dad's 2002 Sonoma crew pickup. Several oil leaks>

What is your question?

Several oil leaks on the pickup. Been sitting for over a year due to my dad's health. Been told from a mechanic that head gaskets are leaking, timing cover, value covers and oil pan gaskets need replaced should buy a new engine. This seems a little extreme, the vehicle has 99,500 miles on it. What could it be, would a dye test be recommended. is the engine shot? Please help. Do head gaskets leak, I understand value covers but never heard about head gaskets. Thank you