How do i know what to do and can you me because i really need it i am failing chemistry because it is too hard.

Exothermic:

An Exothermic reaction is a chemical reaction that expels energy in the form of heat/light. Everything a Endothermic does not do. Pretty simple for this one

reactants → products + energy.

For future reference - Exo means release, thermic means heat.

Energy is a Reactant

Endothermic:

An Endothermic reaction essentially is draining the heat energy from anything its its surroundings. Usually its just heat but can also be salt dissolving it water or ice melting. Another example would be frost on your windshield evaporating.

It is the exact opposite of an Exothermic reaction.

Energy is a Product