Arborists learn all sorts of things including climbing, rope work, safety with saws, root structures, etc. See https://en.wikipedia.org/wiki/Arborist for an overview. If you just want to ID trees, take photos of as many of the base, bark, leaves, flowers, seeds and general growth habit as you can, then upload to iNaturalist.org to get an ID.
Curious if anyone here has any books they would recommend on tree identification and maintenance?