@BillsBayou has it right, this is a grafted tree.
The pot size is not too small, if media is draining well, you could put off repotting until next year.
About training bonsai, you never automatically chop, prune, trim, pinch or wire without a plan, or goal in mind. So putting up the photos, and asking where to chop is meaningless, because you have not told us what image you want to create. Different images, designs, would require different techniques. So tell us what you would like to see this become. It is your tree, you get to draw the picture for the future.
Personally, I love a weeping tree. I also love the normal upright form of bald cypress. If you are willing to put a decade in to the project, the tree could become two or more nice trees, one weeping, one upright. If you are in a hurry, this tree does not have much potential.
Keep it growing, stand it in a tray of water a few inches deep for the summer, it will help speed growth. Moderate fertilizer and full sun are good.
In June, when weather is warm attempt to root an air layer of the weeping part. Make your attempt as far from the trunk graft as possible. Reason is that there is a better than 50:50 chance the layer will fail. You want to have plenty of weeping tree left in case you kill your first attempt. Do only one air layer at a time, ignore those who say you can do multiple air layers. Your new at this, BC is not as easy as an elm to air layer. It may even take more than one season to root. Don't rush it. I have had JBP take 2 and 3 years to root. I also have had about half fail. It is not fool proof.
Once the first air layer has rooted, you remove it, pot it up and then decide if you want a second own root weeping BC.
That is what I would do this year with you tree.