Present. perfect + past perfect

None of that seems to make sense, temporal or otherwise, because of the clause that begins it yet seems totally irrelevant. Please explain what it is that you want to say.

What I'm trying to say is that I didn't ask my parents for money since the moment I've got my first job. (or had got my first job).

And I had to get used to having my own money, but still it feels new.

So I said, "I would have had to get used to it (but I haven't), I haven't asked my parents for money (for a very long time) since I'd got my first job".

Does it make sen

It makes little sense. If there was some requirement for you to get used to having your own money but you did not get used to it, then it's: I should have got used to having my own money.

As for the second part, a past perfect is not correct: I haven't asked my parents for money since I got my first job.

Oh, right! I should have used "should", thank you.

So, do I understand it right that in constructions like this we have to use past simple for the action after since?
I don't understand why, though. We talk about past

Could we say: "Since I've got my first job, I didn't ask my parents for money."?
Can you explain the logic we use to make a sentence like this?

(1) I haven't asked my parents for money (2) since I got my first job.