Where did people in the late middle ages/early renaissance (around 1450 to 1500) get their wood from? I couldn't find any professions such as "lumberjack" from that time, so did it even exist or would a builder just send someone into the woods to fell some trees? Was it maybe the work of a carpenter? I'm especially interested in central Europe.
Hello and welcome.
While you wait for an in-depth response, here's some past answer to get you started.
By /u/idjet, a lovely detailing of forest management (in the context of charcoal production). It contains some information which may be of use to you.
https://www.reddit.com/r/AskHistorians/comments/42mpu4/why_did_charcoal_production_cause_massive/
Central Europe was pretty well settled in the period you're interested in, perhaps the absence of a forest where one could just 'send someone into' would be an interesting fact for you. Credits to /u/Miles_Sine_Castrum and /u/EvanRWT.
I hope these posts can at least get you started.
Cheers.