One thing that I hear consistently from new knitters that is confusing to them is figuring out what the right side is versus the wrong side when it comes to knitting. The "right" side means the side that faces out on a garment or other project: the outside of a sweater or bag, or the pretty side of a scarf or afghan, assuming the stitch you used isn't reversible.
If you're working in Stockinette Stitch, the flat side with all the Vs on it is the "right" side, while the bumpy purl side is the "wrong" side. If your pattern calls for Reverse Stockinette, it's the opposite.
It's pretty easy to tell right from wrong with a stitch that doesn't look the same on both sides, but what about Garter Stitch, ribbing or something else that looks the same on either side? In that case, if you have instructions that call for shaping, say, on every other right side row, you'll need to decide which side is right and which side is wrong and stick with that consistently.
You can stick a locking stitch marker on one side of the work when you get started and declare that side the right side, or you can wait until you need to decide which side is the right side and pick the side that looks prettier to you. It really doesn't matter which side you choose, as long as you're consistent about it.