The って is used in the sense of:
The って is used to introduce a topic (as if quoting it) with a light exclamation/admiration. It can be rephrased as ～というのは.
Which of the following is a better translation:
1. When you go out into society, ...
Both, kind of. It's an adverbial noun (noun that can behave like an adverb), so you can treat it like you would any other number + counter.
So your first sentence is almost correct (skip the に):
Alternatively, you can use の instead to use it attributively (but not な):
Some fun trivia:
ある is the opposite of ない, but ある is a verb and ない is an adjective. How does that make any sense!? The words like 動詞 (literally "act word") and 形容詞 ("descriptive word") make it sound like words are classified by their meaning, but really they are classified more from the perspective of how they fit the grammar rules, I think.
When decorating ...
It is simply the adverbal forms of adjectives.
For い-adjectives, the ending is changed to く:
For な-adjectives, a に is added to the end:
The only exception I can think of at the top of my head is いい -> よく (comes from よい)
I don't think that the て-form and the continuative form verbs qualify as an "adverbial" form, but at least they add meaning to the following verb just like adverbs.
流れている (流れる, an ichidan verb, in the て-form)
ご飯を食べて寝る* (食べる, an ichidan verb, in the て-form)
*everything preceding the て-form verb is included in the "adverbial"...
Joining two statements
Broadly speaking, the く ending allows the meaning of the first statement to broadly modify the second, while くて puts an end on the first statement and separates it more from the second statement.
Let's look at the specific sample sentence in the linked thread.
Here, we basically have two ...
For 近い and 近く, try to think of 近い as an adjective meaning "close", "nearby", and 近く as an adverb (?) meaning "in the vicinity".
The station is nearby.
(lit)The station is in the vicinity of the supermarket = The station is near the supermarket.
Or these examples might help from Reddit discussion:
Q. Can all these 12 adverbial cases in English be expressed by Japanese particle に?
A. Some, yes. Not all.
As Sonny365 TANAKA mentioned, に can be applied to some of them, but not all.
Also, there're sentences which can be understood, but not natural with に.
I don't remember Japanese grammar well, so instead of that, let me translate them into natural ...
I think "When you go out into society, it can be so difficult" focuses "after going out into society" and "Going out into society can be so difficult" focuses "the moment to go out into society". Am I right?
社会に出るって、大変ですね can mean both meanings but I think it seems to focus "after going out into society". 社会に出るのが大変ですね focuses " the moment to go out into ...