“How often do you get the opportunity to move to another country?”
You were offered a job in another country and are telling your friend about it. You think that you're going to take the job because it's an interesting change and something that you won't have another chance to do later in life. This is how you explain why you're going to take the job.
How often do you get the opportunity to move to another country?
There are two meanings of the question "how often do you ___?" The first is the literal meaning. How many times per month, per year, etc. does something happen? For example:
A: How often do you work out?
B: Probably two or three times a week.
The other meaning is a rhetorical meaning. You ask "how often do you ___?" to express that something doesn't happen very much. Here's an example of that use:
Wow, your son actually keeps his room clean without you asking? How often do you hear about that?
In the example at top, the speaker is saying that people don't often get the chance to move to another country. That's why the speaker is going to take the job.
When you "get the opportunity" to do something, it means that you are allowed to do something that you think is good.
An "opportunity" is usually something that you want to do to improve yourself, like something related to work, or to an activity that you like doing such as sports or music.
When you're talking about the person who does the action, you say "get an opportunity":
She got the opportunity to meet with a lot of famous film directors and producers.
When you're talking about the person who lets you or helps you do the action, you say "give ___ an opportunity":
Our mission is to give disadvantaged children the opportunity to grow and achieve their dreams.