Trouble starting is mostly due to problems with the ignition system (distributor, sparks, ignition coil,...) and fuel system.. Check those first.
Overheating problems on the other hand, are due to faults in the water pump, clogged radiator or a stuck thermostat. Coolant overflowing to the reservoir tank might indicate a bad radiator cap, a leaking head gasket or worst case, a cracked head..
my atos dying already.., fix it or sell it?