If you are that confused you need to read more about redox. Here are some things to memorize about redox.
Oxidation is the loss of electrons.
Reduction is the gain of electrons.
(There is a mnemonic aid for this. It is Leo goes grr. From the word Leo, loss of electrons oxidation. OK?). I NEVER tried to remember the definition of oxdn AND reduction because that way I always mixed them up. So I remember ONE of them, namely, that oxidn is the loss of electrons. Then I know reduction must be the opposite. So when you write the half equation, adding electrons is reduction and losing them is oxidation. Now, how do you know what is oxidized and what is reduced. You can tell by the change in oxidation state. Do you know the rules? Here is a simple set.
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Here is a simple equation.
C + O2 ==> CO2.
The oxidation state of C changes from zero on the left to +4 on the right. That means it must have lost 4 electrons which means C was oxidized. Oxygen changes from zero on the left to -2 (for each of them) on the right which means oxygen gained two electrons for each atom of oxygen and that makes oxygen reduced. One set that often confuses students is oxidizing agent and reducing agent. Again, I NEVER memorized EITHER of them. One I know what is oxidized, I immediately know it is the reducing agent. So the "other material" must be reduced and be the oxidizing agent.
I hope this gets you started. Post again if you still have trouble after digesting this information.
Thanks. You broke it down so much better than my professor. :)