Ah, a new tree. I have a lot of those! I keep them in nursery pots. And I repot them. Some are in grow boxes made from wood, some are in pots made from clay.
What is the best tactic for a new tree?
1. Find out what kind of tree it is. A pine is not a spruce. A spruce is not a juniper. A beech is not a birch. They all have different requirements. - It depends.
1.5 Find out what needs priority. If the soil is perfect, then repotting isn't needed right away. If there are branches forming bulges on the trunk that will ruin the tree, then cut those branches first and leave the soil for next year. With some trees, you can do all at once. If the tree is in a bad shape, then it's better to prioritize getting it back to health. - It depends.
2. Find out what the right season for a technique is, for that particular plant. If you repot a pine when it's freezing outdoors, it might not survive. If you do it in the middle of summer, it could die as well. And so on.. - It depends.
3. Think before you act. Does a tree really need a top pruning? Is there another way to achieve the same visual goal without damaging anything? - It depends.
If you can get behind that logic, then you can find out on your own about what to do and when to do it. There are no absolute rules; some people love repotting in mid summer, some people love the spring. If you know what you're doing and why you're doing it and you have a solid reason to do something, then you can't fail. I, and a lot of other newbies tend to overlook (at least) one of those tree points. We fail, we learn, we don't make the same mistake. Or we learn something new about how to hide mistakes, or to regrow a branch. Get your mind set on spending a few years looking at trees in development.
The hardest part is knowing when to do nothing, and actually doing nothing.
That's hypocritical, coming from me. But just a few more broken branches and I'll get my own message too.