I apologize if this is in the wrong forum.

Anyway, I created a ronin character who uses both unarmored and light armor. For the RP I plan to do with him he joins the Imperial Legion for a little bit. I don't really intend to "cheat" per say but I would like to know if there's a way to change my initial Imperial Chain Cuirass (medium armor) to light armor through console commands so I still get the experience for wearing it.

No, consoles command cannot alter the game in that way.
But you could quickly make a mod that changes that armor from being Medium to Light.

Thanks a bunch!

Hmm, now that I think about it I think I should have chosen medium armor/unarmored instead of light armored/unarmored. Is there anyway to change a major/minor skill through the console commands?

You can use the EnableStatReviewMenu to change skills.

Note that there are problems with this method, as you will lose all your spells and your immunity to all diseases.
So it might be easier to just start a new character if you have not got too far.