What is the correct way to ask about a job experience? Did you already work with digital content creation? or Have you already worked with digital content creation?

I am studying three colorations EVEN THEN EVEN SO EVEN THOUGH Then I created some sentences using it: I was trying to buy a new iPhone and the salesman told me that if buy with him I will earn 10% of discount. EVEN SO it’s something that I can’t afford. I was trying to buy a new iPhone and the salesman told me that if buy with him I will earn 10% of discount. EVEN THOUGH it’s something that I can’t afford. I was trying to buy a new iPhone and the salesman told me that if buy with him I will earn 10% of discount. EVEN THEN it’s something that I can’t afford. May I use it this way?

If I’d want to know how time someone spent studying something, for example medicine. I saw in some places that I need use, something like this: “How long have you been studying medicine for” But, I can’t understand why I need use FOR at end.

Guys, see the following situation: At school, all the time me and my friend sit near of each other. But, at day of Math exam, the teacher made a rearrangement. And he was sitting far from me. If someone ask me about him, could I say? “He got far from me now” I am learning the verb GET. That’s why I am doing this question 👍