Hi! I am new to Blender, so sorry if I am using the wrong terms. Currently, I am working on a tutorial (https://m.youtube.com/?#/watch?v=2R-dTzM9LEM) and around 8:33, he aligns the yellow dot (again, I am pretty sure this is not the right term) with the bottom of the leaf. Now, I am quite a bit farther in the tutorial, and I was having a few problems…I decided that I think that the reason is because I did not align the yellow dot with the bottom of the leaf. I tried moving the leaf to the dot, but the dot moves according to the leaf. My proportional editing is not on. If anybody has any advice, it would be appreciated. Thanks.
That’s because you move the leaf in Object mode. You need to do this in Edit mode…
The yellow dot is the pivot point of the leaf (or the origin)
you can’t physically move the “dot” as such . not in the same way as you can move vertices.
the dot is the origin point of the object and is a fixed position that is used for rotating and scaling, as well as the connecting point for procedures such as parenting and constraints, to mention but a few of it’s uses. there are a couple of ways to re locate the origin position, the simplest being to simply go into edit mode and move the entire mesh to where the origin is in the place you need it. as the origin remains fixed in edit mode. the other way is to use the 3D cursor, that little red target thingy.
in edit mode again select the vertices on the model where you want the origin point to be. in your case that would be the vertices at the bottom of the mesh, themn pres ctrl s and choose cursor to selected from the menu. then jump into object mode and in the tool bar panel there is a button labled “set origin”, press that then choose origin to 3D cursor and the origin will now be set to the bottom of your mesh in the exact spot of the 3D cursor. though if you move the cursor later the origin will remain where it was set, so nothing to worry about there 
Thanks, I really appreciate it!