Yes, when you’re fairly new at sharpening you might want to make your passes from the heel to the tip each time. After a while you’ll naturally go back and forth. When you reach the portion of the knife where it begins to curve toward the tip, the tendency is to pull the knife handle toward yourself. But doing so changes the bevel angle. The proper technique is to lift the handle away from the belt and continue to move the blade while still maintaining edge contact. Do it a few times with the belt shut off.
Hold the knife against the angle guide with the cutting edge against the belt. When grinding the edge, you can do it edge leading (the belt moving toward the knife) or edge trailing (the belt moving away from the knife). But you must always strop edge trailing—you’ll probably cut the leather strop if you try to strop edge leading.
Edge leading will cut a bit faster and raise the burr faster.
When grinding, you’ll want to count your passes until you raise a burr from heel to tip on the side you weren’t grinding on. Then make the same number of passes on the other side. Keep grinding and count the additional passes if you don’t raise a burr after making an equal number of passes. When you finally raise a full-length burr on the second side, go back to the first side and make the same number of additional passes. The idea is to make the same number of grinding passes on both sides so that you have a symmetrical bevel.
Starting on an old cheap knife is a good idea. You may want to consider buying a couple of throw away knives from a second hand store. I’ll send you a few if Mayberry doesn’t have a Goodwill or such. You can sharpen them and then dull them up on a brick and go again.
Like most things that are worthwhile, the more you do it the easier it’ll become.
One of my coaches gave me a piece of advice that applies to all aspects of life, “If you want to improve your performance, do more of what you least like to do.”