Novice here. Making it go the tree way instead of the shrub way? [View all]

So last year planted some 1-gallon trees that sprung nicely to shoulder height by winter, but they developed many side branches that were making a shrub out of things. They weathered the winter and I waited for the almost-over winter pruning, when I trimmed off the side branches and chose the one most straight-up one to be the dominant trunk. So far so good.

Now in New Spring, the supposed trunk is sprouting leaf buds, great signs of life, but they are located all up and down the trunk, from LOW on up. I'm guessing this will turn it back into a shrub?

The very top tips of the trunks *do* look like they froze at the very top of the trunk, so is nothing going to happen up there? Do I keep lopping the side sprouts? I want to make trees. Help/thanks.