I am a beginner by all means but do you mean wait with digging up a tree (yamadori?) or outdoors generally?
I wanna get to it and learn by doing but I also want to allow myself for the best possible circumstances.
I'll try to get a hold of more locally engaged bonsai knowledge, it is however limited in Sweden from what I've gathered. Just a couple thousand throughout the entire country!
That was a big vague yeah, here's the expanded version what I'd do if put in your shoes; make it myself as easy as possible to learn the most from whatever hands-(n)on source available. Studying how trees grow by watching some wild examples up close through the seasons for example will help a lot later on by knowing the ways of your potted trees.
Getting some established potted material of native species is also a great way to see what trees do on a detailed scale. Applying hands-non knowledge, like books, Bnut etc, on them is a great next step to maximise your learning curve. The array of reputable sources have the ability to guide the direction of the curve past a lot of hiccups and dips. Distinguishing those reputable sources is someting else sometimes though
Then when these have made it through the winter, in spring I'd dig up some seedlings with some extra extra space around. You'll get maximum roots and a special view of proportions (diameter next to the trunk versus length to the longest tips), which will help later on by guesstimating how long roots of larger specimens will need to be to explain nebari size, as well as to see how much you will need to take home and give a low-key opportunity to practice post rootwork care. Of course that's not nearly all there is to success of yamadori hunting (or bonsai design) but it's one of those multi-connecting puzzle pieces.
And by the time that's all happened you've probably read half the internet on bonsai so no need to worry about that yet, there's several stages of increasingly targeted and puzzling questions first anyway

At least discerning the diamonds in the dust will come even more natural by then.
Keeping it fun maybe be the most important to maximise your studying efforts though, bonsai already is a slow moving and complicated hobby in itself so boredom sometimes is at risk of striking. Thankfully there's shortcuts, but not all of them lead to success and one too many in a row can lead to a dead tree. Balance is the key and if it's not, adding (or removing) a tree always makes for a new headspace and inspiration.
It sounds like you're on the right way to success, maybe there's someone local to catalyse your growth. Bonsai gardens can appear in the most random spots, I've found. Highlights are an old primary school, a sea-view apartment balcony and across the street from a pot store (yes that one). About where are you located? Bonsainut is a great place to generate local leads and you're not the only Swede here. Hope this clarified some and so, and didn't sound too doomy here and there. Bonsai is fun, I promise!