Can anyone elaborate when/how I'm suppose to use these? I was introduced to them today in class and I'm not completely grasping them.

is it the particles wa and no?

Yes.

Partice 'wa' is used to mark a subject in the sentence. It comes after the subject.
ex:
Watashi wa Stephie desu. (I am Stephie.)

'Watashi' would be the subject of the sentece so 'wa' follows right after it.

Particle 'no' is often used to show possession.
ex.
Kono wa watshi no enpitsu desu. (It is my pencil.)

'No' comes after 'watashi' because it is explaining whose pencil it is.

Actually 'wa' marks the topic (what the sentence is about), while 'ga' marks the subject.

off topic but, i'm pretty sure "Kono wa watshi no enpitsu desu" is incorrect grammar..

if you're gonna use kono you have to use the subject right after - このえんぴつは私の(えんぴつ）です。
The sentence structure works with kore/are/sore etc though.

Eh. Was in a hurry typing it out. I hate typing in romaji. xD Never makes much sense to me.