Me again!
I got it to work and all, but I’m left with a little string of yarn when I can’t make anymore loops. What do I do with it? Tie a knot and cut?
Long tail cast-on Con't
NO, don’t cut it! Leave it long enough to weave in or you can knit the first 3 or 4 stitches with both the working yarn and the left over tail and then you can cut it. Just remember that those first few stitches will be double when you are doing the next row. You just pick up both stitches as one.
Ooh okay!
I was so confused, because my first stitch would loosen because of it and…it was just annoying. 
How exactly would I weave it in?
I believe there are tutorials for weaving in the videos at the top of the forum. Here’s another. It takes practice to get it right just like anything else. 