I actually sat down just last night and made a list of tree species I have, then I looked up and wrote down when to repot, prune, wire etc...
(yep newbee here

- the list is mainly to STOP me from trying to do too much and at the wrong time of year - aka fiddling)
Since I am growing most from seed, I'm totally not having much to do just yet. Whatever nursery stock I got, pretty much just got uppotted and pruned a bit this year, I made some plans as to what to do with them if they survive winter, but again, not that much work just yet.
There is no rush, just research what each species needs and keep them alive for a while. Then decide where to cut, wire etc, and do it at the right time of year

If you still feel overwhelmed, just plant some out in the garden for a while...
Have fun